                        課程
                    
                        /前端開發(fā)
                        
                            /JavaScript
                        
                        /JS動(dòng)畫效果

為什么出不來05:00的效果？代碼如下

<!DOCTYPE?HTML>
<html>??
<head>??
<meta?http-equiv="Content-Type"?content="text/html;?charset=UTF-8"?/>??
<title>獲取屬性動(dòng)畫2</title>
<style?type="text/css">
*{margin:0;?padding:0;}

	ul,li{
		list-style:?none;
	}
	ul?li{
		width:?200px;
		height:?100px;
		background:?yellow;
		margin-bottom:?20px;
		border:?10px?solid?#000;
		filter:alpha(opacity:30);
		opacity:0.3;
	}
</style>
<script?type="text/javascript">
	window.onload=function(){
		?var?Li1=document.getElementById('li1');
		?Li1.onmouseover=function(){
		?	startMove(this,'opacity',100);
		?}
		?Li1.onmouseout=function(){
		?	startMove(this,'opacity',30);
		?}
		??
	}
function?getStyle(obj,attr){
	if(obj.currentStyle){
		return?obj.currentStyle[attr];}//針對(duì)IE瀏覽器
		else{
			return?getComputedStyle(obj,false)[attr];//針對(duì)火狐瀏覽器
		}
	
}
//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.width=icur+speed+'px';
			?obj.style[attr]=icur+speed+'px';
		????????????????????}
	????}
	},30)
}?
</script>?
</head>
<body>
	<ul>
		<li?id="li1"></li>
????</ul>
</body>
</html>