<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta http-equiv="X-UA-Compatible" content="ie=edge" />
<title>拖拽放大</title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
#div1{
position: relative;
width: 200px;
height: 200px;
background-color: pink;
}
#div2{
position: absolute;
width: 50px;
height: 50px;
right: 0;
bottom: 0;
background-color: cornflowerblue;
}
</style>
</head>
<body>
<div id="div1">
<div id="div2"></div>
</div>
<script type="text/javascript">
var div1=document.querySelector('#div1')
var div2=document.querySelector('#div2')
div2.onmousedown=function(e){
var x=e.pageX;
var y=e.pageY;
var width=div1.offsetWidth
var height=div1.offsetHeight
document.onmousemove=function(e){
div1.style.width=width+e.pageX-x+'px'
div1.style.height=height+e.pageY-y+'px'
}
}
div2.onmouseup=function(){
document.onmousemove=null
}
</script>
</body>
</html>