<!DOCTYPE html>
<html >
<head>
<meta charset="UTF-8">
<title>js 放大镜</title>
<script src="https://code.jquery.com/jquery-3.3.1.js"></script>
<style>
*{
margin: 0;
padding: 0;
}
.tu{
width: 500px;
}
.box{
border:1px solid #000;
width: 200px;
height: 200px;
}
.box{
background:url("https://gdp.alicdn.com/imgextra/i3/3446533752/TB2n3A7fOCYBuNkHFCcXXcHtVXa_!!3446533752.jpg") no-repeat;
}
</style>
</head>
<body>
<img class="tu" src="https://gdp.alicdn.com/imgextra/i3/3446533752/TB2n3A7fOCYBuNkHFCcXXcHtVXa_!!3446533752.jpg" alt="">
<div class="box"></div>
<script>
$(function(){
console.log("1");
$(".tu").mousemove(function(even){
console.log(even)
console.log(even.clientX);
console.log(even.clientY);
$(".box").css("background-position","-"+even.clientX+"px -"+even.clientY+"px")
});
})
</script>
</body>
</html>