<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
body{
height:5000px;
}
#side{
width: 50px;
height: 100px;
background-color: #000000;
position:absolute;
right: 0;
top:45%;
}
</style>
</head>
<body>
<div id="side">
</div>
<script src="js/jquery-1.9.1.min.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
$(function() {
var $sidebar = $("#side");
var $window = $(window);
$window.scroll(function() {
$sidebar.stop(true).animate({
‘marginTop‘: $window.scrollTop()
},1000);
});
window.onload=function(){
$(window).trigger(‘scroll‘); //页面加载完毕后自动触发事件
};
$(window).resize(function(){
$(window).trigger(‘scroll‘); //刷新窗口的scroll事件
})
});
</script>
</body>
</html>
原文：http://www.cnblogs.com/luoguixin/p/6271598.html