简单运动问题
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>简单运动</title>
<style type="text/css">
#div1{
width: 200px;
height: 200px;
background-color: red;
position: relative;
left: -200px;
top: 0;
}
#div1 span{
width: 20px;
height: 50px;
background-color:blue;
position: absolute;
left: 200px;
top: 75px;
}
</style>
<script type="text/javascript">
window.onload=function(){
var myDiv=document.getElementById('div1');
myDiv.onmouseover=function(){
startMove(0);
}
myDiv.onmouseout=function(){
startMove(-200);
}
}
var timer=null;
function startMove(iTarget){
clearInterval(timer);
var myDiv=document.getElementById('div1');
timer=setInterval(function(){
var speed=0;
speed=speed>0?Math.ceil(speed):Math.floor(speed);
if (myDiv.offsetLeft>iTarget) {
speed=-10;
} else {
speed=5;
}
if (myDiv.offsetLeft==iTarget) {
clearInterval(timer);
}
else{
myDiv.style.left=myDiv.offsetLeft+speed+'px';
}
},20);
}
</script>
</head>
<body>
<div id="div1">
<span id="share">分享</span>
</div>
</body>
</html>为什么不是0和-200，总会多出来个8px，而且出来和退出的速度明显不一样呢。。。
