<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<style>
div{
100px;
height:100px;
background-color:red;
position:absolute;
left:100px;
top:100px;
}
</style>
</head>
<body>
<div id="div1"></div>
<script>
var div1 = document.getElementById("div1");
var l = false,
t = false,
r = false,
b = false;
document.onkeydown = function(ev) {
switch (ev.keyCode) {
case 37:
l = true;
break;
case 38:
t = true;
break;
case 39:
r = true;
break;
case 40:
b = true;
break;
}
if (l) {
div1.style.left = div1.offsetLeft - 5 + "px";
}
if (t) {
div1.style.top = div1.offsetTop - 5 + "px";
}
if (r) {
div1.style.left = div1.offsetLeft + 5 + "px";
}
if (b) {
div1.style.top = div1.offsetTop + 5 + "px";
}
}
document.onkeyup = function() {
l = false;
t = false;
r = false;
b = false;
}
</script>
</body>
</html>