$(function(){ //置顶按钮显示/隐藏实现 $(window).scroll(function(){ var w_height = $(window).height();//浏览器高度 var scroll_top = $(document).scrollTop();//滚动条到顶部的垂直高度 if(scroll_top > w_height){ $("#goto-top").fadeIn(500); }else{ $("#goto-top").fadeOut(500); } }); //置顶 $("#goto-top").click(function(e){ e.preventDefault(); $(document.documentElement).animate({ scrollTop: 0 },200); //支持chrome $(document.body).animate({ scrollTop: 0 },200); }); }) </script> <style type="text/css"> #goto-top { display:none; position:fixed; width:38px; height:36px; background:url(images/goto-top.png) no-repeat 0 0; bottom:40px; right:40px; -webkit-transition:all 0.2s; -moz-transition:all 0.2s; -o-transition:all 0.2s; transition:all 0.2s; z-index:9999; } #goto-top:hover { background:url(images/goto-top.png) no-repeat 0 -36px; } </style> </head>