<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
*{padding:0;margin:0;}
ul,li{
list-style:none;
}
ul li{
width:200px;
height: 100px;
background: yellow;
margin-bottom:20px;
}
</style>
<script>
window.onload=function(){
var oLi=document.getElementsByTagName('li');
for(var i=0,l=oLi.length;i<l;i++){
this.onmouseover=function(){
move(this,400);
}
this.onmouseout=function(){
move(this,200);
}
}}
var timer=null;
function move(obj,iTarget){
clearInterval(timer);
timer=setInterval(function(){
var speed=(iTarget-obj.offsetWidth)/2>0?Math.ceil(speed):Math.floor(speed);
if(obj.offsetWidth==iTarget){
clearInterval(timer);
}else{
obj.style.width=obj.offsetWidth+speed+'px';//这里的obj.style一直显示未定义
}
},50);
}
</script>
</head>
<body>
<ul>
<li></li>
<li></li>
<li></li>
</ul>
</body>
</html>
参照你的代码看看，也许对你有帮助
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
*{padding:0;margin:0;}
ul,li{
list-style:none;
}
ul li{
width:200px;
height: 100px;
background: yellow;
margin-bottom:20px;
}
</style>
<script>
window.onload=function(){
var oLi=document.getElementsByTagName('li');
for(var i=0;i<oLi.length;i++){
oLi[i].onmouseover=function(){/*有改动*/
move(this,400);
}
oLi[i].onmouseout=function(){{/*有改动*/
move(this,200);
}
}}
var timer=null;
function move(obj,iTarget){
clearInterval(timer);
timer=setInterval(function(){
var speed=(iTarget-obj.offsetWidth)/8;{<!--有改动，原来的那样写运算次序有问题-->
var speed=speed>0?Math.ceil(speed):Math.floor(speed);
if(obj.offsetWidth==iTarget){
clearInterval(timer);
}else{
obj.style.width=obj.offsetWidth+speed+'px';//这里的obj没问题
}
},50);
}
</script>
</head>
<body>
<ul>
<li></li>
<li></li>
<li></li>
</ul>
</body>
</html>
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
*{
margin: 0px;
padding: 0px;
}
ul,li{
list-style: none;
}
ul li{
width: 200px;
height: 100px;
background:yellow;
margin-bottom:20px;
}
</style>
<script type="text/javascript">
window.onload = function(){
var aLi = document.getElementsByTagName('li');
for(var i = 0. i < aLi.length; i++){
aLi[i].onmouseover = function(){
startMove(this, 400);
}
aLi[i].onmouseout = function(){
startMove(this, 200);
}
}
}
var timer = null;
function startMove(obj, Target){
clearInterval(timer);
timer = setInterval(function(){
var speed = (Target - obj.offsetWidth)/8;
speed = (speed > 0) ? Math.ceil(speed): Math.floor(speed);
if(obj.offsetWidth == Target){
clearInterval(timer);
}
else{
obj.style.width = obj.offsetWidth + speed + 'px';
}
}, 30)
}
</script>
</head>
<body>
<ul>
<li></li>
<li></li>
<li></li>
</ul>
</body>
</html>
首先。
for(var i=0,l=oLi.length;i<l;i++){
this.onmouseover=function(){
这里就不该直接用this，而应该使用
oLi[i].onmouseover=function(){}
因为你遍历循环的时候没指名是哪个object在里面，所以this是属于window object。而不是具体的某个html元素。