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

頁面沒有反應

<!DOCTYPE?html>
<html>
<head>
<meta?charset="UTF-8">
<title>鏈式運動框架</title>
<style?type="text/css">
body,ul,li{
margin:?0;
padding:?0;
}
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?type="js/move.js"></script>
<script>
window.onload=function(){
var?Li=document.getElementById("li1");
Li.onmouseover=function(){
startMove(Li,"width",400,function(){
startMove(Li,"height",200,function(){
startMove(Li,"opacity",100);
});
});
};

Li.onmouseout=function(){
startMove(Li,"opacity",30,function(){
startMove(Li,"height",100,function(){
startMove(Li,"width",200);
});
});
};

};
</script>
</head>
<body>
<ul>
<li?id="li1"></li>
</ul>
</body>
</html>

js/move.js

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

function?startMove(obj,attr,iTarget,fn){
	clearInterval(obj.timer);
	obj.timer=setInterval(function(){
		//獲取當前屬性值
		var?icur;
		if(attr=="opacity"){
			icur=Math.round(parseFloat(getStyle(obj,attr))*100);
		}else{
			icur=parseInt(getStyle(obj,attr));
		}
		//計算變化速度
		var?speed=(iTarget-icur)/8;
		speed=speed>0?Math.ceil(speed):Math.floor(speed);
		//檢測停止
		if(icur==iTarget){
			clearInterval(obj.timer);
			if(fn){?//當某一動畫結束時，如果有回調函數，則執(zhí)行
				fn();
			}

		}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);
}