以下就是全部代碼（純Js）
<!DOCTYPE html>
<html>
<head>
<title>follow mouse</title>
</head>
<style type="text/css">
*{
margin: 0;
padding:0;
}
#div1{
width: 50px;
height: 50px;
border-radius: 50%;
background: red;
color:#fff;
text-align: center;
line-height: 50px;
position: absolute;
transition: all 0.5s; }
#div2{
width: 50px;
height: 50px;
border-radius: 50%;
background: green;
color:#fff;
text-align: center;
line-height: 50px;
position:absolute;
transition: all 0.5s; }
.box1{
width: 100%;
height: 400px;
border: 1px solid #ccc;
}
.box2{
width: 100%;
height: 400px;
border: 1px solid #ccc;
}
</style>
<body>
<div class="box1" onmousemove="b1()">
<div id="div1" >1</div>
</div>
<div class="box2" onmousemove="b2()">
<div id="div2">2</div>
</div>
</body>
<script type="text/javascript">
function b1(ev) {
var oEvent = ev || event;
var oDiv = document.getElementById('div1');
if( oEvent.clientX<1350&&oEvent.clientY<350){
oDiv.style.left = oEvent.clientX + 'px';
oDiv.style.top = oEvent.clientY + 'px';
}
}
function b2(ev){
var oEvent=ev||event;
var oDiv=document.getElementById('div2');
if( oEvent.clientX<350&&oEvent.clientY<750){
oDiv.style.left=oEvent.clientX+'px';
oDiv.style.top=oEvent.clientY+'px';
}
}
</script>
</html>
效果圖：
