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鼠标划入，透明度一直往上涨。似乎无法判断到itarget==alpha这个情况。求大神帮忙看看代码

<!DOCTYPE html>
<html>
<head>
 <meta charset="UTF-8">
 <title>完美框架</title>
 <style type="text/css">
  body,ul{
   margin: 0px;
   padding: 0px;
  }
  ul,li{
   list-style: none;
  }
  ul li{   width: 200px;
   height: 100px;
   float:left;
   background: red;
   margin-right: 20px;
   opacity: 0.3;
  }
 </style>
 <script type="text/javascript">
 window.onload=function(){
  var aLi =document.getElementsByTagName('li');
  for (var i = aLi.length - 1; i >= 0; i--) {
    aLi[i].timer=null;
    aLi[i].alpha=0.3;
   aLi[i].onmouseover=function(){
                 startMove(this,1.0);
   }
   aLi[i].onmouseout=function(){
     startMove(this,0.3);
   }  }
  }
  //var timer=null;
  function startMove(obj,iTarget){
   clearInterval(obj.timer);
   var speed=iTarget-obj.alpha;
   obj.timer=setInterval(function(){
       
                speed=speed>0?0.1:-0.1; 
    
   if (iTarget==obj.alpha) {
    clearInterval(obj.timer);
   }else{    obj.alpha+=speed;
    obj.style.opacity=obj.alpha;
   } 
   },30);
   
  }
 </script>
</head>
<body>
 <ul>
  <li></li>
  <li></li>
  <li></li>
 </ul>
</body>
</html>

qq_弃子_0

2016-12-11

源自：JS动画效果 4-1

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1 回答

694710752
2016-12-11

这样就可以了，

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>完美框架</title>
<style type="text/css">
body,ul{
   margin: 0px;
   padding: 0px;
}
ul,li{
   list-style: none;
}
ul li{   width: 200px;
   height: 100px;
   float:left;
   background: red;
   margin-right: 20px;
   filter:alpha(opacity:30);
   opacity: 0.3;
}
</style>
<script type="text/javascript">
window.onload=function(){
var aLi =document.getElementsByTagName('li');
for (var i = aLi.length - 1; i >= 0; i--) {
    aLi[i].timer=null;
    aLi[i].alpha=30;
   aLi[i].onmouseover=function(){
     startMove(this,100);
   }
   aLi[i].onmouseout=function(){
     startMove(this,30);
   } }
}

function startMove(obj,iTarget){
   clearInterval(obj.timer);
var speed=iTarget-obj.alpha;   obj.timer=setInterval(function(){
           speed=speed>0?10:-10;
   if (iTarget==obj.alpha) {
    clearInterval(obj.timer);
   }else{    obj.alpha+=speed;
    obj.style.filter='alpha(opacity:'+obj.alpha+')';
   obj.style.opacity=obj.alpha/100;
   }
   },30);

}
</script>
</head>
<body>
<ul>
<li></li>
<li></li>
<li></li>
</ul>
</body>
</html>