<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>mask</title>
<style>
.pic{
width:300px;
height:250px;
background:url(icon/product1.jpg) no-repeat;
margin:40px auto;
}
#mask{
width:300px;
height:250px;
background-color: gray;
margin:40px auto;
opacity: 0.5;
z-index: 1000;
}
</style>
</head>
<body>
<div class="pic">
<!-- <div id="mask"></div> -->
</div>
</body>
<script>
var pic=document.getElementsByClassName("pic")[0];
var d=document.createElement("div");
pic.onmouseenter=function(){
// var d=document.createElement("div");
d.id="mask";
pic.appendChild(d);
};
pic.onmouseleave=function(){
this.removeChild(d);
};
</script>
</html>
效果图：
