常见于GIS行业,下面列子中使用了两张图片的卷帘对比效果，效果图如下：
image.png
<html><head>
<title>前后对比</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta http-equiv="Content-Language" content="zh-CN">
<link href="css/roll.css" type="text/css" rel="stylesheet">
<style type="text/css">
.beforeafter{
width: 940px;
height: 529px;
}
#after{
position: absolute;
top: 0px;
left: 0px;
background-image: url(./2.jpg);
width: 940px;
height: 529px;
background-repeat: no-repeat;
}
#before{
position: absolute;
top: 0px;
left: 0px;
border-right: 3px solid #f00;
background-image: url(./1.jpg);
width: 433px;
height: 529px;
background-repeat: no-repeat;
max-width: 940px;
}
</style>
<script src="./jquery-1.12.3.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
function RollImage(evt){
var x=evt.pageX;
$("#before").css("width",x+"px");
}
</script>
</head>
<body>
<div class="beforeafter" onmousemove="RollImage(event)">
<div id="after"></div>
<div id="before"> </div>
</div>
</body>
</html>
