写了一个非常简单的 jQuery 插件实例 浮动层随窗口滚动滑动
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-1.8.1.min.js"></script>
<script type="text/javascript">
(function($){
$.fn.floatAutoScroll = function(){
this.each(function(){
var obj = $(this);
var top = obj.css('top').replace('px', '');
$(window).scroll(function(){
var scrollTop = $(window).scrollTop();
obj.stop().animate({ top:(top*1 + scrollTop*1) }, 'normal');
});
});
}
})(jQuery);
$(function(){
$('.float-container').floatAutoScroll();
});
</script>
<style type="text/css">
.main { height:1500px; }
.float-container { position:absolute; right:0; 50px; height:50px; background-color:#960; }
.float1 { top:100px; }
.float2 { top:200px; }
.float3 { top:300px; }
</style>
</head>
<body>
<div class="main"></div>
<div class="float-container float1">浮动框1</div>
<div class="float-container float2">浮动框2</div>
<div class="float-container float3">浮动框3</div>
</body>
</html>