我检查了代码 没有问题但是 还是提示错误 Uncaught TypeError: Cannot read property 'currentStyle' of undefined 求大神啊！！
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>多物体运动3</title>
<style>
body,div,span{
margin:0 !important;
padding:0 !important;
}
ul,li {
list-style: none;
}
ul li {
width: 200px;
height: 100px;
background: yellow;
margin-bottom:20px;
border: 4px solid #000;
filter:alpha(opacity:30);
opacity: 0.3;
}
</style>
<script>
window.onload = function(){
/*var aLi = document.getElementsByTagName('li');
for(var i = 0; i<aLi.length; i++){
aLi[i].timer = null;
aLi[i].onmouseover = function(){
startMove(this,400);
}
aLi[i].onmouseout = function(){
startMove(this,200);
}
}*/
var li1 = document.getElementById('li1');
var li2 = document.getElementById('li2');
li1.onmouseover = function(){
startMove(this,'opacity',100);
}
li1.onmouseout = function(){
startMove(this,'opacity',30);
}
}
//获取样式
function getStyle(obj,attr){
if(obj.currentStyle){
return obj.currentStyle[attr];
}
else{
return getComputedStyle(obj,false)[attr];
}
}
//var timer = null;
var alpha = 30;
function startMove(obj,attr,iTarget){
clearInterval(obj.timer);
obj.timer = setInterval(function(){
var icur = 0;
if(attr == 'opacity'){
icur = parseFloat(getStyle(obj.attr))*100;
}
else{
icur = parseInt(getStyle(obj,attr));
}
var speed = (iTarget-icur)/8;
speed = speed>0?Math.ceil(speed):Math.floor(speed);
if(icur == iTarget){
clearInterval(obj.timer)
}
else{
if(attr == 'opacity'){
obj.style.filter = 'alpha(opacity:'+(icur + speed)+')';
obj.style.opacity = (icur + speed)/100;
}
else{
obj.style[attr] = icur + speed + 'px';
}
}
},30)
}
</script>
</head>
<body>
<ul>
<li id="li1"></li>
</ul>
</body>
</html>
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