慕课网javascript动画特效 多透明度 源代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>多物体运动</title>
<style>
div{
width:200px;
height:100px;
background:yellow;
margin-bottom: 20px;
filter:alpha(opacity:0.3);
opacity:0.3;
}
</style>
<script>
window.onload=function(){
var ali=document.getElementsByTagName(‘div‘);
for(var i=0;i<ali.length;i++){
ali[i].alpha=30;
ali[i].timer=null
ali[i].onmouseover=function(){
startMove(this,100);
}
ali[i].onmouseout=function(){
startMove(this,30);
}
}
}
// var timer=null;
// var alpha=30;
// ali[i].alpha=30;
function startMove(obj,iTarget){
clearInterval(obj.timer);
obj.timer=setInterval(function(){
var speed=0;
if(obj.alpha>iTarget){
speed=-10;
}else{
speed=10;
}if(obj.alpha==iTarget){
clearInterval(obj.timer);
}
else{
obj.alpha+=speed;
obj.style.filter=‘alpha(opacity:‘+obj.alpha+‘)‘;
obj.style.opacity=obj.alpha/100;
}
},30)
}
</script>
</head>
<body>
<div id="div1"></div>
<div id="div2"></div>
<div id="div3"></div>
<div id="div4"></div>
</body>
</html>
慕课网地址http://www.imooc.com/video/2880
原文：http://www.cnblogs.com/milkytea/p/6986143.html