求教：为什么透明度最终回不到1了啊啊啊啊啊???
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>js动画案例</title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
#div1{
padding: 10px;
width: 300px;
background-color: #f4f4f4;
margin: 10px auto;
border: 1px solid #ccc;
}
#div1 a{
display: inline-block;
width: 58px;
height: 25px;
border: 1px solid #ddd;
border-radius: 3px;
background-color: #fff;
text-align: center;
margin: 10px 17px;
position: relative;
padding-top: 40px;
color: #9c9c9c;
font-size: 12px;
text-decoration: none;
line-height: 25px;
overflow: hidden;
}
#div1 a i{
position: absolute;
top: 20px;
left: 0px;
display: inline-block;
width: 100%;
text-align: center;
filter:alpha(opacity=100);
opacity: 1;
}
#div1 a:hover{
color: #f00;
}
</style>
<script src="move.js"></script>
<script type="text/javascript">
window.onload=function(){
var oDiv= document.getElementById('div1');
var aList= oDiv.getElementsByTagName('a');
for(i=0; i<aList.length; i++){
aList[i].onmouseover= function(){
var _this= this.getElementsByTagName('i')[0];
startMove(_this,{top:-25,opacity:0},function(){
_this.style.top= 30+'px';
startMove(_this,{top:20,opacity:100});
})
}
}
}
</script>
</head>
<body>
<div id='div1'>
<a href="#"><i><img src="baobei.png"></i><p>宝贝</p></a>
<a href="#"><i><img src="dianpu.png"></i><p>店铺</p></a>
<a href="#"><i><img src="sheying.png"></i><p>摄影</p></a>
<a href="#"><i><img src="wenzhang.png"></i><p>文章</p></a>
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<a href="#"><i><img src="tupian.png"></i><p>图片</p></a>
</div>
</body>
</html>
下面是运动框架:
// function startMove(obj,attr,iTarget,fn) {
function startMove(obj,json,fn) {
clearInterval(obj.timer);
obj.timer= setInterval(function(){
for(var attr in json){
//1.取当前的值
var incur=0;
var flag= true;
if(attr=='opacity'){
incur=Math.round(parseFloat(getStyle(obj,attr))*100);
}else{
incur=parseInt(getStyle(obj,attr));
}
//2.算速度
var speed= (json[attr]-incur)/15;
speed= speed>0?Math.ceil(speed):Math.floor(speed);
//3.检测停止
if(incur!=json[attr]){
flag= false;
if(attr=='opacity'){
obj.style.filter='alpha(opacity:'+(incur+speed)+')';
obj.style.opacity=(incur+speed)/100;
}else{
obj.style[attr]=incur+speed+'px';
}
}
if(flag){
clearInterval(obj.timer);
if(fn){
fn();
}
}
}
},20)
}
function getStyle(obj,attr){
if(obj.currentStyle){
return obj.currentStyle[attr];//IE
}else{
return getComputedStyle(obj,false)[attr];//firefox
}
}
