AWS Lambda 操作 RDS 示例-CFANZ编程社区

给这个图片添加摄像头图标，并获取图标的坐标值，也就是图标的css样式是positon:absolute,获取left和top的值。

思路是这样的，获取这里的长度，

1.鼠标点击时距浏览器的左边距离和上边距离，相当于(0,0)坐标

let x = e.clientX;
let y = e.clientY;

2.图片距浏览器顶部的距离

let imgTop = $('.imageBox img').offset().top;
let imgLeft = $('.imageBox img').offset().left;

3.就能获取到图片2中箭头的距离，即鼠标点击的位置距背景图顶部的距离

let cursorTop = y - imgTop;
let cursorLeft = x - imgLeft;

4.计算得出图标的left和top值，这里是%。

let width = $('.imageBox img').width();
let height = $('.imageBox img').height();
let left = (cursorLeft/width*100).toFixed(2)
let top = (cursorTop/height*100).toFixed(2)

5.效果如下图，但是鼠标点击处是图标的左上角，感觉好像是差一点

6.应该让鼠标点击处是图标的中心，就需要获取图标中心的坐标，然后减去图片2中箭头的距离。

//设置添加的小图标的center为中心点
let  pointLeft = $('.imageBox .block').width()*0.5;
let  pointTop = $('.imageBox .block').height()*0.5;

//鼠标点击无差距
let xData = cursorLeft - pointLeft;
let yData = cursorTop - pointTop;

7. 完整代码如下

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
		.imageBox{
			width: 800px;
			position: relative;
			overflow: hidden;
			margin: 5% 2%;
		}
		.imageBox img{
			width: 100%;
			height: 100%;
		}
		.imageBox .block{
			width: 3%;
			height: 4%;
			background: url(camera.png) 0 0 no-repeat;
			background-size: 100% 100%;
			position: absolute;
			
		}
		</style>
	</head>
	<body>
		<div class="page">
			<div class="imageBox">
				<img src="https://img0.baidu.com/it/u=3593454291,2854711423&fm=253&fmt=auto&app=138&f=JPEG?w=800&h=500" >
				<div class="block">

				</div>
			</div>
		</div>
		<script src="jquery.min.js" type="text/javascript" charset="utf-8"></script>
		<script type="text/javascript">
			$('.imageBox').click(function(e){
				//鼠标点击时距浏览器的左边距离和上边距离，相当于(0,0)坐标
				let x = e.clientX;
				let y = e.clientY;

				//图片的宽高
				let width = $('.imageBox img').width();
				let height = $('.imageBox img').height();

				//图片距浏览器顶部的距离
				let imgTop = $('.imageBox img').offset().top;
				let imgLeft = $('.imageBox img').offset().left;

				//鼠标点击的位置距背景图顶部的距离
				let cursorTop = y - imgTop;
				let cursorLeft = x - imgLeft;

				//设置添加的小图标的center为中心点
				let  pointLeft = $('.imageBox .block').width()*0.5;
				let  pointTop = $('.imageBox .block').height()*0.5;

				//鼠标点击无差距
				let xData = cursorLeft - pointLeft;
				let yData = cursorTop - pointTop;


				let left = (xData/width*100).toFixed(2)
				let top = (yData/height*100).toFixed(2)
				console.log(x);
				console.log(y);
				// let html = `<div class="block" style="top: ${top}%;left: ${left}%;"></div>`
				// $('.imageBox').append(html);
				$('.imageBox .block').css({'top':top+'%'})
				$('.imageBox .block').css({'left':left+'%'})

			})
		</script>
	</body>
</html>