深入理解BootStrap -- 按钮组工具栏9

1、按钮（按钮组）

单个按钮在Web页面中的运用有时候并不能满足我们的业务需求，常常会看到将多个按钮组合在一起使用，比如富文本编辑器里的一组小图标按钮等。那么在这一节中，我们主要向大家介绍Bootstrap框架为大家提供的按钮组组件。

源码查询：

按钮组也是一个独立的组件，所以可以找到对应的源码文件：

​​buttons.less​​​​_buttons.scss​​

☑ CSS版本：对应bootstrap.css文件第3131行～第3291行

使用方法：

​​bootstrap.js​​文件。因为这个文件已集成了button.js插件功能。​​“btn-group”​​的容器，把多个按钮放到这个容器中。如下所示：

<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn-group"</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"glyphicon glyphicon-step-backward"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"glyphicon glyphicon-fast-backward"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"glyphicon glyphicon-backward"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"glyphicon glyphicon-play"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"glyphicon glyphicon-pause"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"glyphicon glyphicon-stop"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"glyphicon glyphicon-forward "</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"glyphicon glyphicon-fast-forward"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"glyphicon glyphicon-step-forward"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>

运行效果如下所示： 

​​<button>​​元素之外，还可以使用其他标签元素，比如​​<a>​​标签。唯一要保证的是：不管使用什么标签，​​“.btn-group”​​容器里的标签元素需要带有类名​​“.btn”​​。

按钮组实现源码如下：

查看bootstrap.css文件第3131行～第3161行/

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group-vertical {
  position: relative<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
  display: inline-block<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
  vertical-align: middle<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
}
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group-vertical > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span> {
  position: relative<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
  float: left<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
}
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>:hover,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group-vertical > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>:hover,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>:focus,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group-vertical > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>:focus,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>:active,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group-vertical > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>:active,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.active</span>,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group-vertical > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.active</span> {
  <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">z</span>-index: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
}
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>:focus,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group-vertical > <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>:focus {
  outline: none<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
}
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span> + <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span> + <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group + <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>,
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group + <span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.btn</span>-group {
   margin-left: -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>px<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</l

i></ul>

从效果图上我们可以看出，按钮组四个角都是圆角（支持CSS3的浏览器），但有的小伙伴会问，我们平常制作网页时每个按钮都是带有圆角，而在按钮组中的按钮，除了第一个和最后一个具有边上的圆角之外，其他的按钮没有圆角，它是怎么实现的呢？其实实现方法非常简单：

• 1、默认所有按钮都有圆角
• 2、除第一个按钮和最后一个按钮（下拉按钮除外），其他的按钮都取消圆角效果
• 3、第一个按钮只留左上角和左下角是圆角
• 4、最后一个按钮只留右上角和右下角是圆角

对应的源码如下：

查看bootstrap.css文件第3174行～第3203行/

<code class="hljs lasso has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>):<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>):<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>dropdown<span class="hljs-attribute" style="box-sizing: border-box;">-toggle</span>) {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span> {
  margin<span class="hljs-attribute" style="box-sizing: border-box;">-left</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>):<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>dropdown<span class="hljs-attribute" style="box-sizing: border-box;">-toggle</span>) {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-top</span><span class="hljs-attribute" style="box-sizing: border-box;">-right</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-bottom</span><span class="hljs-attribute" style="box-sizing: border-box;">-right</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>),
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>dropdown<span class="hljs-attribute" style="box-sizing: border-box;">-toggle</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>) {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-top</span><span class="hljs-attribute" style="box-sizing: border-box;">-left</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-bottom</span><span class="hljs-attribute" style="box-sizing: border-box;">-left</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> {
  float: left;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>):<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>) <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span><span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>,
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span><span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>dropdown<span class="hljs-attribute" style="box-sizing: border-box;">-toggle</span> {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-top</span><span class="hljs-attribute" style="box-sizing: border-box;">-right</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-bottom</span><span class="hljs-attribute" style="box-sizing: border-box;">-right</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span><span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span> {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-top</span><span class="hljs-attribute" style="box-sizing: border-box;">-left</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-bottom</span><span class="hljs-attribute" style="box-sizing: border-box;">-left</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li></ul>

2、按钮（按钮工具栏）

在富文本编辑器中，将按钮组分组排列在一起，比如说复制、剪切和粘贴一组；左对齐、中间对齐、右对齐和两端对齐一组，如下图所示：

​​“btn-group”​​按组放在一个大的容器​​“btn-toolbar”​​中，如下所示：

<code class="hljs applescript has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-toolbar"</span>>
  <<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-group"</span>>
    …
  </<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>>
  <<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-group"</span>>
    …
  </<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>>
  <<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-group"</span>>
    …
  </<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>>
  <<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-group"</span>>
    …
  </<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>>
</<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li></ul>

​​“btn-group”​​元素进行浮动，并且组与组之前保持​​5px​​的左外距。代码如下：

源码请查阅bootstrap.css文件第3162行～第3173行/

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-toolbar</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">margin-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> -<span class="hljs-number" style="box-sizing: border-box;">5</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-toolbar</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-toolbar</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.input-group</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">float</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> left</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-toolbar</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-toolbar</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-toolbar</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.input-group</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">margin-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">5</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul>

注意在​​”btn-toolbar”​​上清除浮动。

源码请查阅bootstrap.css文件第5062行/

<code class="hljs scss has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box;">.btn-toolbar</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:before</span>,
<span class="hljs-class" style="box-sizing: border-box;">.btn-toolbar</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:after</span>｛
　<span class="hljs-attribute" style="box-sizing: border-box;">display</span><span class="hljs-value" style="box-sizing: border-box;">: table;</span>
<span class="hljs-attribute" style="box-sizing: border-box;">content</span><span class="hljs-value" style="box-sizing: border-box;">: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" "</span>;</span>
｝
<span class="hljs-class" style="box-sizing: border-box;">.btn-toolbar</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:after</span>{
  <span class="hljs-attribute" style="box-sizing: border-box;">clear</span><span class="hljs-value" style="box-sizing: border-box;">: both;</span>
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>

运行效果如下：

按钮组大小设置

在介绍按钮一节中，我们知道按钮是通过btn-lg、btn-sm和btn-xs三个类名来调整padding、font-size、line-height和border-radius属性值来改变按钮大小。那么按钮组的大小，我们也可以通过类似的方法：

☑ .btn-group-lg:——大按钮组

☑ .btn-group-sm:——小按钮组

☑ .btn-group-xs:——超小按钮组

只需要在“.btn-group”类名上追加对应的类名，就可以得到不同大小的按钮组。如下所示：

<code class="hljs applescript has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-toolbar"</span>>
  <<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-group btn-group-lg"</span>>
    …
  </<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>>
  <<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-group"</span>>
    …
  </<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>>
  <<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-group btn-group-sm"</span>>
    …
  </<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>>
  <<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-group btn-group-xs"</span>>
   …
  </<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>>
</<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li></ul>

实现按钮组大小效果样式代码如下：

源码请查阅bootstrap.css文件第2320行～第2340行/

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-lg</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group-lg</span>> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span><span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">10</span>px <span class="hljs-number" style="box-sizing: border-box;">16</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">font-size</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">18</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">line-height</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">1.33</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">6</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-sm</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group-sm</span>> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-number" style="box-sizing: border-box;">10</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">font-size</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">12</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">line-height</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">1.5</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">3</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-xs</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group-xs</span>> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span><span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">1</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">font-size</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">12</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">line-height</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">1.5</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">3</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li></ul>

3、按钮（嵌套分组）

很多时候，我们常把下拉菜单和普通的按钮组排列在一起，实现类似于导航菜单的效果。如下所示：

​​“dropdown”​​的容器换成​​“btn-group”​​，并且和普通的按钮放在同一级。如下所示：

<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn-group"</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btnbtn-default"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span>></span>首页<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btnbtn-default"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span>></span>产品展示<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btnbtn-default"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span>></span>案例分析<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btnbtn-default"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span>></span>联系我们<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn-group"</span>></span>
       <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btnbtn-default dropdown-toggle"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">data-toggle</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"dropdown"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span>></span>关于我们<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"caret"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
       <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">ul</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"dropdown-menu"</span>></span>
             <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>公司简介<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
             <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>企业文化<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
             <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>组织结构<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
             <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>客服服务<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
        <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">ul</span>></span>
    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li></ul>

实现的样式代码：

查看bootstrap.css文件第3192行～第3223行/

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">float</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> left</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:not(</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:first-child)</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:not(</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:last-child)</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:first-child</span>> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:last-child</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:first-child</span>> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-top-right-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-bottom-right-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:last-child</span>> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:first-child</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-top-left-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-bottom-left-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:active</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.open</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">outline</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span> + <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding-right</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">8</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">8</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-lg</span> + <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding-right</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">12</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">12</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.open</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> inset <span class="hljs-number" style="box-sizing: border-box;">0</span> <span class="hljs-number" style="box-sizing: border-box;">3</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-function" style="box-sizing: border-box;">rgba(<span class="hljs-number" style="box-sizing: border-box;">0</span>, <span class="hljs-number" style="box-sizing: border-box;">0</span>, <span class="hljs-number" style="box-sizing: border-box;">0</span>, .<span class="hljs-number" style="box-sizing: border-box;">125</span>)</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> inset <span class="hljs-number" style="box-sizing: border-box;">0</span> <span class="hljs-number" style="box-sizing: border-box;">3</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-function" style="box-sizing: border-box;">rgba(<span class="hljs-number" style="box-sizing: border-box;">0</span>, <span class="hljs-number" style="box-sizing: border-box;">0</span>, <span class="hljs-number" style="box-sizing: border-box;">0</span>, .<span class="hljs-number" style="box-sizing: border-box;">125</span>)</span></span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.open</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-link</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> none</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> none</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li></ul>

4、按钮（垂直分组）

​​“btn-group”​​类名换成​​“btn-group-vertical”​​即可。 运行的效果如下： 

实现垂直分组的样式代码：

请查看bootstrap.css文件第3234行～第3276行/

<code class="hljs lasso has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn,
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>,
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn {
  display: block;
  float: <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">none</span>;
  width: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span><span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">%</span>;
  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">max</span><span class="hljs-attribute" style="box-sizing: border-box;">-width</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span><span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">%</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn {
  float: <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">none</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">+</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn,
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">+</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>,
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">+</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn,
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">+</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span> {
  margin<span class="hljs-attribute" style="box-sizing: border-box;">-top</span>: <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">-</span><span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>px;
  margin<span class="hljs-attribute" style="box-sizing: border-box;">-left</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>):<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>) {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>) {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-top</span><span class="hljs-attribute" style="box-sizing: border-box;">-right</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>px;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-bottom</span><span class="hljs-attribute" style="box-sizing: border-box;">-right</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-bottom</span><span class="hljs-attribute" style="box-sizing: border-box;">-left</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>) {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-top</span><span class="hljs-attribute" style="box-sizing: border-box;">-left</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-top</span><span class="hljs-attribute" style="box-sizing: border-box;">-right</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-bottom</span><span class="hljs-attribute" style="box-sizing: border-box;">-left</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>px;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>):<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>) <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>) <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>,
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>) <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>dropdown<span class="hljs-attribute" style="box-sizing: border-box;">-toggle</span> {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-bottom</span><span class="hljs-attribute" style="box-sizing: border-box;">-right</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-bottom</span><span class="hljs-attribute" style="box-sizing: border-box;">-left</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span><span class="hljs-attribute" style="box-sizing: border-box;">-vertical</span> <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn<span class="hljs-attribute" style="box-sizing: border-box;">-group</span>:last<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">not</span>(:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span>) <span class="hljs-subst" style="color: rgb(0, 0, 0); box-sizing: border-box;">></span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">.</span>btn:first<span class="hljs-attribute" style="box-sizing: border-box;">-child</span> {
  border<span class="hljs-attribute" style="box-sizing: border-box;">-top</span><span class="hljs-attribute" style="box-sizing: border-box;">-left</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
  border<span class="hljs-attribute" style="box-sizing: border-box;">-top</span><span class="hljs-attribute" style="box-sizing: border-box;">-right</span><span class="hljs-attribute" style="box-sizing: border-box;">-radius</span>: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li></ul>

和水平分组按钮不一样的是：

☑ 水平分组按钮第一个按钮左上角和左下角具有圆角以及最后一个按钮右上角和右下角具有圆角

☑ 垂直分组按钮第一个按钮左上角和右上角具有圆角以及最后一个按钮左下角和右下角具有圆角

5、按钮（等分按钮）

等分按钮的效果在移动端上特别的实用。整个按钮组宽度是容器的100%，而按钮组里面的每个按钮平分整个容器宽度。例如，如果你按钮组里面有五个按钮，那么每个按钮是20%的宽度，如果有四个按钮，那么每个按钮是25%宽度，以此类推。

​​“btn-group”​​上追加一个​​“btn-group-justified”​​类名，如下所示：

<code class="hljs applescript has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span> <span class="hljs-type" style="box-sizing: border-box;">class</span>=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"btn-group btn-group-justified"</span>></<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">div</span>></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

运行效果如下：

​​“btn-group-justified”​​模拟成表格​​（display:table）​​，而且把里面的按钮模拟成表格单元格​​（display:table-cell）​​。具体样式代码如下：

源码请查看bootstrap.css文件第3277行～第3291行/

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group-justified</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">display</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> table</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">100</span>%</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">table-layout</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> fixed</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-collapse</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> separate</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group-justified</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group-justified</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">display</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> table-cell</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">float</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> none</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">1</span>%</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group-justified</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">100</span>%</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li></ul>

​​<a>​​标签元素来制作按钮，因为使用​​<button>​​标签元素时，使用​​display:table​​在部分浏览器下支持并不友好。

6、按钮下拉菜单

​​.btn​​）样式效果。简单点说就是点击一个按钮，会显示隐藏的下拉菜单。​​“<a>”​​标签元素换成了​​“<button>”​​标签元素。唯一不同的是外部容器​​“div.dropdown”​​换成了​​“div.btn-group”​​。如下所示：

<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn-group"</span>></span>
      <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default dropdown-toggle"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">data-toggle</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"dropdown"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span>></span>按钮下拉菜单<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"caret"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
      <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">ul</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"dropdown-menu"</span>></span>
          <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>按钮下拉菜单项<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
          <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>按钮下拉菜单项<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
          <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>按钮下拉菜单项<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
          <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>按钮下拉菜单项<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
      <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">ul</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>

实现样式代码如下：

查看bootstrap.css文件第3204行～第3223行/

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:active</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.open</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">outline</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span> + <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding-right</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">8</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">8</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span> > <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-lg</span> + <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding-right</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">12</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">padding-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">12</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.open</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> inset <span class="hljs-number" style="box-sizing: border-box;">0</span> <span class="hljs-number" style="box-sizing: border-box;">3</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-function" style="box-sizing: border-box;">rgba(<span class="hljs-number" style="box-sizing: border-box;">0</span>, <span class="hljs-number" style="box-sizing: border-box;">0</span>, <span class="hljs-number" style="box-sizing: border-box;">0</span>, .<span class="hljs-number" style="box-sizing: border-box;">125</span>)</span></span></span>;
          <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> inset <span class="hljs-number" style="box-sizing: border-box;">0</span> <span class="hljs-number" style="box-sizing: border-box;">3</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-function" style="box-sizing: border-box;">rgba(<span class="hljs-number" style="box-sizing: border-box;">0</span>, <span class="hljs-number" style="box-sizing: border-box;">0</span>, <span class="hljs-number" style="box-sizing: border-box;">0</span>, .<span class="hljs-number" style="box-sizing: border-box;">125</span>)</span></span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-group</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.open</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown-toggle</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-link</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> none</span></span>;
          <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> none</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li></ul>

运行的效果如下：

7、按钮的向下向上三角形

​​<button>​​标签中添加一个​​“<span>”​​标签元素，并且命名为​​“caret”​​:

<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default dropdown-toggle"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">data-toggle</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"dropdown"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span>></span>按钮下拉菜单<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"caret"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>

这个三角形完全是通过CSS代码来实现的：

源码请查看bootstrap.css文件第2994行～第3003行/

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.caret</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">display</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> inline-block</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">height</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">margin-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">2</span>px</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">vertical-align</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> middle</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-top</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">4</span>px solid</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-right</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">4</span>px solid transparent</span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">4</span>px solid transparent</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul>

​​“caret”​​做了一定的样式处理：

源码查看bootstrap.css文件第3224行～第3233行/

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.caret</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">margin-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-lg</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.caret</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-bottom-width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropup</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.btn-lg</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.caret</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span> <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul>

​​“.btn-group”​​类上追加​​“dropup”​​类名（这也是做向上弹起下拉菜单要用的类名）。

源码请查看bootstrap.css文件第3109行～第3114行/

<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropup</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.caret</span>,
<span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.navbar-fixed-bottom</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.dropdown</span> <span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.caret</span> <span class="hljs-rules" style="box-sizing: border-box;">{
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">content</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">""</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-top</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">0</span></span></span>;
  <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-bottom</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">4</span>px solid</span></span>;
<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>

​​border-bottom​​的值。

下面是向上弹起菜单的例子：

<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn-group dropup"</span>></span>
  <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"btn btn-default dropdown-toggle"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">data-toggle</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"dropdown"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"button"</span>></span>按钮下拉菜单<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"caret"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">span</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">button</span>></span>
  <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">ul</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">class</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"dropdown-menu"</span>></span>
        <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>按钮下拉菜单项<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
        <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>按钮下拉菜单项<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
        <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>按钮下拉菜单项<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
        <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">href</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"##"</span>></span>按钮下拉菜单项<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">a</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">li</span>></span>
  <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">ul</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">div</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>

运行效果如下：