<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
*{
margin:0;
padding:0;
box-sizing:border-box;
}
div{
width: 200px;
height: 200px;
background: blue;
border-radius: 50%;
position:fixed;
}
span{
width: 100px;
height: 100px;
text-align: center;
line-height: 100px;
border-radius: 50%;
position: absolute;
background:#ccc;
margin-left: 50px;
margin-top:50px;
}
</style>
</head>
<body>
<div style="left:0;top:0"><span>X</span></div>
</body>
</html>
<script>var oDiv=document.getElementsByTagName('div')[0];
var ospan=document.getElementsByTagName("span")[0];
var i=1,j=1;
var timer=setInterval(fn,30)
function fn(){
oDiv.style.left=oDiv.offsetLeft+10*i+"px";
oDiv.style.top=oDiv.offsetTop+10*j+"px";
var ymWidth=document.documentElement.clientWidth||document.body.clientWidth;
var ymHeight=document.documentElement.clientHeight||document.body.clientHeight;
if (oDiv.offsetLeft>=ymWidth-200&&i>0||oDiv.offsetLeft<=0&&i<0) {
i*=-1;
}
if (oDiv.offsetTop>=ymHeight-200&&j>0||oDiv.offsetTop<=0&&j<0) {
j*=-1;
};
}
oDiv.onmouseover=function(){
clearInterval(timer)
}
oDiv.onmouseout=function(){
timer=setInterval(fn,30)
}
ospan.onclick=function(){
oDiv.style.display="none"
}
var timer2=setInterval(function(){
oDiv.style.display="block"
},2000)
</script>
