jQuery实现返回顶部 

<!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>
<title>仿新浪网“返回顶部”效果</title>
<meta http-equiv="content-type" content="text/html;charset=gb2312">
<style type="text/css">
.backToTop {
 display: none;
 width: 18px;
 line-height: 1.2;
 padding: 5px 0;
 background-color: #000;
 color: #fff;
 font-size: 12px;
 text-align: center;
 position: fixed;
 _position: absolute;
 right: 10px;
 bottom: 100px;
 _bottom: "auto";
 cursor: pointer;
 opacity: .6;
 filter: Alpha(opacity=60);
}
</style>
<script type="text/javascript" src="http://jqueryjs.googlecode.com/files/jquery-1.3.2.min.js"></script>
</head>
<body>
<div style="height:2000px;"></div>
<script type="text/javascript">
(function() {
    var $backToTopTxt = "返回顶部", $backToTopEle = $('<div class="backToTop"></div>').appendTo($("body"))
        .text($backToTopTxt).attr("title", $backToTopTxt).click(function() {
            $("html, body").animate({ scrollTop: 0 }, 120);
    }), $backToTopFun = function() {
        var st = $(document).scrollTop(), winh = $(window).height();
        (st > 0)? $backToTopEle.show(): $backToTopEle.hide();
        //IE6下的定位
        if (!window.XMLHttpRequest) {
            $backToTopEle.css("top", st + winh - 166);
        }
    };
    $(window).bind("scroll", $backToTopFun);
    $(function() { $backToTopFun(); });
})();
</script>
</body>
</html>

 

posted @ 2013-12-10 16:19  白小虫  阅读(269)  评论(0)  编辑  收藏  举报