固定浮动侧边栏(SmartFloat)

<!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=gb2312" />
<title>固定浮动侧边栏</title>
<style type="text/css">
	body {
		margin: 10px auto;
		font-family: sans-serif;
		width: 500px;
	}
	
	div {
		border-radius: 5px;
		box-shadow: 1px 2px 5px rgba(0,0,0,0.3);
		border: 1px solid #ccc;
		padding: 5px;
	}
	
	#sidebarWrap {
		height: 400px;
		width: 210px;
		float: right;
		position: relative;
		box-shadow: none;
		border: none;
		margin: 0;
		padding: 0;
	}
	
	#main {
		width: 270px;
		height: 4000px;
	}
	
	#footer {
		clear: both;
		margin: 10px 0;
	}
	
	#sidebar {
		width: 200px;
		height: 300px;
		position: absolute;
	}
	
	#header {
		height: 200px;
		margin-bottom: 10px;
	}
	
	#sidebar.fixed {
		position: fixed;
		top: 0;
	}
	
	#footer { height: 600px; }
</style>
</head>

<body>
    <div id="header">header</div>
    
    <div id="sidebarWrap">
        <div id="sidebar">Sidebar</div>
    </div>
    
    <div id="main">
        Main
    </div>
    
    <div id="footer">
        footer
    </div>
</body>
</html>
<script src="../Js/jquery.min.js"></script>
<script type="text/javascript">
$(function() {
    var top = $('#sidebar').offset().top - parseFloat($('#sidebar').css('marginTop').replace(/auto/, 0));
    var footTop = $('#footer').offset().top - parseFloat($('#footer').css('marginTop').replace(/auto/, 0));

    var maxY = footTop - $('#sidebar').outerHeight();

    $(window).scroll(function(evt) {
        var y = $(this).scrollTop();
        if (y > top) {
            if (y < maxY) {
                $('#sidebar').addClass('fixed').removeAttr('style');
            } else {
                $('#sidebar').removeClass('fixed').css({
                    position: 'absolute',
                    top: (maxY - top) + 'px'
                });
            }
        } else {
            $('#sidebar').removeClass('fixed');
        }
    });
});
</script>

posted @ 2014-07-08 10:46  网事  阅读(237)  评论(0编辑  收藏  举报