简单的 jQuery 浮动层随窗口滚动滑动插件实例

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; width: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>