<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
div {
width: 100px;
height: 100px;
background: red;
margin: 10px;
filter: alpha(30);
opacity: 0.3;
}
</style>
<script>
window.onload = function() {
var aDiv = document.getElementsByTagName(‘div‘);
var i = 0;
for (i = 0; i < aDiv.length; i++) {
aDiv[i].alpha = 30;
aDiv[i].onmouseover = function() {
startMove(this, 100);
}
aDiv[i].onmouseout = function() {
startMove(this, 30);
}
}
}
// var alpha = 30;
function startMove(obj, iTarget) { //多物体运动所有东西都不能共用
clearInterval(obj.timer);
obj.timer = setInterval(function() {
var iSpeed = (iTarget - obj.alpha) / 8;
iSpeed = iSpeed > 0 ? Math.ceil(iSpeed) : Math.floor(iSpeed);
if (obj.alpha == iTarget) {
clearInterval(obj.timer);
} else {
obj.alpha += iSpeed;
obj.style.filter = ‘alpha(opacity:‘ + obj.alpha + ‘)‘;
obj.style.opacity = obj.alpha / 100;
}
}, 30)
}
</script>
</head>
<body>
<div></div>
<div></div>
<div></div>
<div></div>
</body>
</html>
原文：http://www.cnblogs.com/Mr-W/p/6406985.html