“返回顶部”代码效果

<!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>
    <p>
        如果预览时左下角提示错误，<font color="red">请先刷新一下本页面</font>就可以看到效果了。</p>
    <p>
        拖动滚动条到页面底部就会显示“返回顶部”按钮。</p>
    <p>
        更多代码请访问：<a href="http://www.lanrentuku.com/" target="_blank">懒人图库</a></p>
    <p>
    </p>
    <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>

 

 

 

 

二、

*{padding:0; margin:0}
body{height:2000px}
#totop{position:fixed;bottom:40px;right:10px;z-index:999;width:71px; cursor:pointer; display:none;}
*html #totop{position:absolute;cursor:pointer;right:10px; display:none;top:expression(eval(document.documentElement.scrollTop+document.documentElement.clientHeight)-112+"px")}
#totop a{display:block;width:71px;height:24px;padding-top:48px;background:url(../images/toTop.gif) no-repeat;text-align:center;color:#888}
#totop a.cur{background-position:-88px 0;text-decoration:none;color:#3a9}

 

$(function() {
02     $.fn.manhuatoTop = function(options) {
03         var defaults = {           
04             showHeight : 150,
05             speed : 1000
06         };
07         var options = $.extend(defaults,options);
08         $("body").prepend("<div id='totop'><a>返回</a></div>");
09         var $toTop = $(this);
10         var $top = $("#totop");
11         var $ta = $("#totop a");
12         $toTop.scroll(function(){
13             var scrolltop=$(this).scrollTop();     
14             if(scrolltop>=options.showHeight){              
15                 $top.show();
16             }
17             else{
18                 $top.hide();
19             }
20         });
21         $ta.hover(function(){      
22             $(this).addClass("cur");   
23         },function(){          
24             $(this).removeClass("cur");    
25         });
26         $top.click(function(){
27             $("html,body").animate({scrollTop: 0}, options.speed); 
28         });
29     }
30

});

 

用法如下：
<script type="text/javascript">
$(function (){
	$(window).manhuatoTop({
		showHeight : 100,//设置滚动高度时显示
		speed : 500 //返回顶部的速度以毫秒为单位
	});
});
</script>

posted on 2012-08-16 17:31  lzf0514  阅读(1001)  评论(0)  编辑  收藏  举报

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