<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
body{
margin:0;
padding:0;
}
ul,li{
margin:0;
padding:0;
}
ul,li{
list-style: none;
}
ul li{
width: 200px;
height: 100px;
background:yellow;
margin-bottom: 20px;
filter:alpha(opacity:30);
opacity: 0.3;
border:4px solid #000;
}
</style>
<script type="text/javascript">
window.onload=function(){
var li1 = document.getElementById('li1');
li1.onmouseover = function(){
startMove(li1,'width',400,function(){
startMove(li1,'height',200,function(){
startMove(li1,'opacity',100)
})
});
}
li1.onmouseout = function(){
startMove(li1,'opacity',30,function(){
startMove(li1,'height',100,function(){
startMove(li1,'width',200)
})
});
}
}
function getStyle(obj,attr){
if(obj.currentStyle){
return obj.currentStyle[attr];
}else{
return getComputedStyle(obj,false)[attr];
}
}
function startMove(obj,attr,target,fn){
clearInterval(obj.timer);
obj.timer=setInterval(function(){
var icur=0;
if(attr == 'opacity'){
var icur = parseFloat(getStyle(obj, attr))*100;
}else{
var icur = parseInt(getStyle(obj, attr));
}
var speed = (target-icur)/8;
speed=speed>0?Math.ceil(speed):Math.floor(speed);
if(icur == target){
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[attr]=icur + speed+'px';
}
}
},30);
}
</script>
</head>
<body>
<ul>
<li id="li1"></li>
</ul>
</body>
</html>
顾名思义,按着顺序进行运动。添加一个函数参数,为下一步所要进行的运动。后面添加一个判定,若有参数传入则执行。注意onmouseout的运动顺序(与onmouseover相反)。另此处this问题,若obj的参数为this,则从第二个开始无效。