<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<style>
#div1{
height:100px;
width:100px;
background:red;
position:absolute;
}
</style>
<script>
window.onload = function ()
{
var odiv = document.getElementById('div1');
var key = { l:null,t:null,r:null,b:null};
setInterval(function ()
{
if(key.l)
odiv.style.left = odiv.offsetLeft + - 10 + 'px';
if(key.t)
odiv.style.top = odiv.offsetTop - 10 + 'px';
if(key.r)
odiv.style.left = odiv.offsetLeft + 10 + 'px';
if(key.b)
odiv.style.top = odiv.offsetTop + 10 + 'px';
},50)
document.onkeydown = function (ev)
{
var ev = ev || event;
switch(ev.keyCode)
{
case 37 :
key.l = true;
break;
case 38 :
key.t = true;
break;
case 39 :
key.r = true;
break;
case 40 :
key.b = true;
break;
}
}
document.onkeyup = function (ev)
{
var ev = ev || event;
switch(ev.keyCode)
{
case 37 :
key.l = false;
break;
case 38 :
key.t = false;
break;
case 39 :
key.r = false;
break;
case 40 :
key.b = false;
break;
}
}
}
</script>
</head>
<body>
<div id="div1"></div>
</body>
</html>