<!DOCTYPE html>
<html lang="en">
<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>遮罩效果实现</title>
<style>
*{
margin:0;
padding:0;
}
.first{
width:200px;
height:200px;
border:2px solid red;
}
.second{
width:150px;
height:150px;
border:2px solid green;
position:relative;
}
.second div{
width:100px;
height:100px;
background:yellow;
}
.second p{
width:100px;
height:100px;
background-color:rgba(0,0,0,0.6);
position:absolute;
top:0;
left:0;
display:none;
color:#fff;
}
</style>
</head>
<body>
<div class="first">
<div class="second">
<div>我是正常显示的内容</div>
<p id="obj">我是遮罩</p>
</div>
</div>
<script>
var second=document.getElementsByClassName("second")[0];
var obj=document.getElementById("obj");
second.onmouseover=function(){
obj.style.display="block";
}
second.onmouseout=function(){
obj.style.display="none";
}
</script>
</body>
</html>