<!DOCTYPE html>
<html lang="en">
<head>
<title>Verlet Shapes</title>
<meta charset="UTF-8" />
<script type="text/javascript" src="jquery-1.11.3.min.js"></script>
<style type="text/css">
*{
margin:auto 0px;
padding:0px;
}
#move{
position:relative;
}
</style>
</head>
<body>
<img src="123.jpg" style="width:200px;height:200px;" id="move">
<script type="text/javascript">
window.onload = function() {
var longx = 10;
var longy = 10;
function imgmove(){
var top = $("#move").offset().top;//获取当前元素距顶部距离
var left = $("#move").offset().left;//获取当前元素距左侧距离
//console.log(top);
//console.log(left);
if(top>=$(window).height()-200||top<0){//判断元素是否移动超出高度范围
longx =-longx;
}
if(left>$(window).width()-200||left<0){//判断元素是否移动超出宽度范围
longy =-longy;
}
top +=longx;
left +=longy;
//console.log(longx);
$("#move").css({"top":top,"left":left});
}
var time1 = setInterval(imgmove,20);
$("#move").mouseover(function(){
clearInterval(time1);
}).mouseout(function(){
time1 = setInterval(imgmove,20);
})
}
</script>
</body>
原文：http://www.cnblogs.com/IsMyWay/p/4911069.html