<!doctype html>
<html>
<head>
<meta charset="utf-8">
<style type="text/css">
#gs{width:100px;height:100px;border:1px solid #000;background-color:#aaa;top:200px;position:relative;}
p{position:fixed;left:10px;top:10px;border:1px solid #f00;}
</style>
<script src="./jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(e){
var startPos=$('#gs').offset();
var step=50;
var endPos={};
var move=function(direction){
switch(direction){
case 'L':
var lf=startPos.left-step;
$.extend(endPos,{left:lf});
break;
case 'R':
var lf=startPos.left+step;
$.extend(endPos,{left:lf});
break;
case 'T':
var tp=startPos.top-step;
$.extend(endPos,{top:tp});
break;
case 'B':
var tp=startPos.top+step;
$.extend(endPos,{top:tp});
break;
}
$('#gs').animate(endPos,'fast',function(){startPos=$('#gs').offset();});
}
$(document).keyup(function(e){
switch(String.fromCharCode(e.keyCode)){
case 'A':
move('L');
break;
case 'D':
move('R');
break;
case 'W':
move('T');
break;
case 'S':
move('B');
break;
}
});
});
</script>
</head>
<body>
<div id="gs"></div>
<p>效果:按下键盘上的A、D、W、S键试试</p>
</body>
</html>