主要是记录div的位置变化。
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>wasd控制移动</title>
<style>
div{
width: 100px;
height:100px;
background-color: #004A87;
}
</style>
</head>
<body>
<div class="box">
</div>
<script>
var box=document.getElementsByClassName("box")[0];
box.style.marginTop=0;
box.style.left=0;
document.οnkeydοwn=function(e){
var e=window.event;
switch (e.keyCode){
case 38:
case 87:
if(box.offsetTop>20){box.style.marginTop=(parseInt(box.offsetTop)-20)+"px";}
break;
case 40:
case 83:
if(box.offsetTop+100<=document.documentElement.clientHeight){box.style.marginTop=(parseInt(box.offsetTop)+20)+"px";}
break;
case 37:
case 65: if(box.offsetLeft>0){box.style.marginLeft=(parseInt(box.offsetLeft)-20)+"px";}
break;
case 39:
case 68:if(box.offsetLeft+100<=document.documentElement.clientWidth){box.style.marginLeft=(parseInt(box.offsetLeft)+20)+"px";}
break;
}
}
</script>
</body>
</html>