<script type="text/javascript"> //返回顶部 function topControl(obj){ var _this=$(obj); $(window).scroll(function(){ if($(this).scrollTop()!=0){ _this.addClass("showThis"); }else{ _this.removeClass("showThis"); } }) } //初始化实例 $(function(){ topControl('.toTop'); }) </script> <style type="text/css"> body{height:2000px}/*只为演示页面出现滚动条*/ .toTop { width: 50px; height: 50px; position: fixed; bottom: 2px; right: -60px; outline: 0; transition: all 1s ease; -webkit-transition: all 1s ease; -moz-transition: all 1s ease; -ms-transition: all 1s ease; _position: absolute; } .toTop.showThis { right: 8px; transform: rotate(-360deg); -webkit-transform: rotate(-360deg); -moz-transform: rotate(-360deg); -ms-transform: rotate(-360deg); } .toTop b { width: 100%; height: 100%; display: block; text-indent: -9999em; background: url(https://www.phpvar.com/wp-content/themes/forigi1.1/images/icon_top.png) no-repeat; } </style> <a href="javascript:;" class="toTop"><b>回顶部</b></a>