今天要分享的是运用原生JS滚动鼠标改变元素大小，效果如下：
以下是代码实现，欢迎大家复制粘贴 。
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>原原生JS滚动鼠标改变元素大小</title>
<style>
#box {
width: 200px;
height: 200px;
background: red;
position: relative;
left:200px;
top:200px;
}
</style>
</head>
<body style="height:2000px;">
<div id="box"></div>
<script>
// 普通事件：onclick、onmousedown
// DOM事件：DOMMouseScroll
// DOM事件只能通过绑定来添加
function myAddEvent(obj, event, callback) {
if (obj.attachEvent) {
obj.attachEvent('on' + event, callback);
} else {
obj.addEventListener(event, callback, false);
}
}
window.onload = function () {
var box = document.getElementById('box');
// 滚动事件
function onMouseWheel(ev) {
var myEvent = ev || event;
var down = true;
// 用于区分是向上滚动还是向下滚动
down = myEvent.wheelDelta ? myEvent.wheelDelta < 0 : myEvent.detail > 0;
if (down) {
box.style.height = box.offsetHeight + 10 + 'px';
} else {
box.style.height = box.offsetHeight - 10 + 'px';
};
if (myEvent.preventDefault) {
myEvent.preventDefault();
};
return false;
};
myAddEvent(box, 'mousewheel', onMouseWheel);
myAddEvent(box, 'DOMMouseScroll', onMouseWheel);
};
</script>
</body>
</html>
