                        課程
                    
                        /前端開發
                        
                            /JavaScript
                        
                        /JS動畫效果

為什么我的回掉函數用不了？

move.js

function?getStyle(obj,attr){
	if(obj.currentStyle){
		return?obj.currentStyle[attr];
	}else{
		return?getComputedStyle(obj,false)[attr];
	}
}

function?starMove(obj,attr,iTarget,fn){
	clearInterval(obj.timer);
	obj.timer?=?setInterval(function(){

		var?icur?=?0;
		if(attr?==?'opacity'){
			icur?=?Math.round(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);
			if(fn){
				fn();
			}
		}else{	
			if(attr?==?'opacity'){
				obj.style.filter?=?'alpha(opacity:"+(icur+speed)+")';
				obj.style.opacity?=?(icur+speed)/100;
			}else{
				obj.style.width?=?icur?+?speed?+?'px';
			}
		}
	},30)
}

html

<!DOCTYPE?html>
<html>
<head>
<meta?charset="UTF-8">
<title>Document</title>
<style?type="text/css">
*{
margin:?0;
padding:?0;
}

ul{
margin-top:?20px;
}
ul,li{
list-style:?none;
}

ul?li{
width:200px;
height:?100px;
background:?red;
margin-bottom:?20px;
filter:alpha('opacity':30);
opacity:?0.3;
border:?1px?solid?#ccc;?
}
</style>
<script?type="text/javascript"?src="js/move.js"></script>
<script?type="text/javascript">
window.onload?=?function(){
var?Li?=?document.getElementById('li1');
Li.onmouseover?=?function(){
starMove(Li,'width',400,function(){
starMove(Li,'height',200);
});
}
}
</script>
</head>
<body>
<ul>
<li?id="li1"></li>
</ul>
</body>
</html>

調用完一次之后無法調用第二次。