js多物体运动之淡入淡出效果

<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Document</title>
</head>
<style>
         div{width:200px;height: 200px;margin: 20px;float: left;
         background-color: red;filter:alpha(opacity:30);opacity: 0.3;}
      
</style>
<body> 
            <div></div>
            <div></div>
            <div></div>
            <div></div>        
           
</body>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
    window.onload=function(){
        var oDiv=document.getElementsByTagName('div');
        for(var i=0;i<oDiv.length;i++){
            oDiv[i].alpha=30;
            oDiv[i].onmouseover=function(){
                
                startMove(this,100);
            };
                oDiv[i].onmouseout=function(){
                startMove(this,30);
            };
        }
                
    };
    
    
        function startMove(obj,iTarget){
            clearInterval(obj.timer);
            obj.timer=setInterval(function(){
                var speed=(iTarget-obj.alpha)/6;
                speed=speed>0?Math.ceil(speed):Math.floor(speed);
                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>
</html>

原文地址:https://www.cnblogs.com/kangshuai/p/7231730.html