<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>手机移动端返回顶部js代码</title> <script src="http://libs.baidu.com/jquery/1.11.3/jquery.min.js"></script> </head> <body style="background-color: #dddfff;"> <div class="headeline"></div> <p style="font-size:24px;color:red;text-align: center;">手机往下滑动即可显示返回顶部按钮!</p> <!--演示内容开始--> <div style="height:2000px;"></div> <!--演示内容结束--> </body> <script> var scrolltotop = { setting: { startline: 100, //起始行 scrollto: 0, //滚动到指定位置 scrollduration: 400, //滚动过渡时间 fadeduration: [500, 100] //淡出淡现消失 }, controlHTML: '<img src="https://cs.m.xczhihui.com/xcview/css/minirefresh/images/minirefresh-totop.png" style="width:66px;height:66px;border:0;" />', //返回顶部按钮 controlattrs: { offsetx: 30, offsety: 80 }, //返回按钮固定位置 anchorkeyword: "#top", state: { isvisible: false, shouldvisible: false }, scrollup: function() { if (!this.cssfixedsupport) { this.$control.css({ opacity: 0 }); } var dest = isNaN(this.setting.scrollto) ? this.setting.scrollto : parseInt(this.setting.scrollto); if (typeof dest == "string" && jQuery("#" + dest).length == 1) { dest = jQuery("#" + dest).offset().top; } else { dest = 0; } this.$body.animate({ scrollTop: dest }, this.setting.scrollduration); }, keepfixed: function() { var $window = jQuery(window); var controlx = $window.scrollLeft() + $window.width() - this.$control.width() - this.controlattrs .offsetx; var controly = $window.scrollTop() + $window.height() - this.$control.height() - this.controlattrs .offsety; this.$control.css({ left: controlx + "px", top: controly + "px" }); }, togglecontrol: function() { var scrolltop = jQuery(window).scrollTop(); if (!this.cssfixedsupport) { this.keepfixed(); } this.state.shouldvisible = (scrolltop >= this.setting.startline) ? true : false; if (this.state.shouldvisible && !this.state.isvisible) { this.$control.stop().animate({ opacity: 1 }, this.setting.fadeduration[0]); this.state.isvisible = true; } else { if (this.state.shouldvisible == false && this.state.isvisible) { this.$control.stop().animate({ opacity: 0 }, this.setting.fadeduration[1]); this.state.isvisible = false; } } }, init: function() { jQuery(document).ready(function($) { var mainobj = scrolltotop; var iebrws = document.all; mainobj.cssfixedsupport = !iebrws || iebrws && document.compatMode == "CSS1Compat" && window.XMLHttpRequest; mainobj.$body = (window.opera) ? (document.compatMode == "CSS1Compat" ? $("html") : $( "body")) : $("html,body"); mainobj.$control = $('<div id="topcontrol">' + mainobj.controlHTML + "</div>").css({ position: mainobj.cssfixedsupport ? "fixed" : "absolute", bottom: mainobj.controlattrs.offsety, right: mainobj.controlattrs.offsetx, opacity: 0, cursor: "pointer" }).attr({ title: "返回顶部" }).click(function() { mainobj.scrollup(); return false; }).appendTo("body"); if (document.all && !window.XMLHttpRequest && mainobj.$control.text() != "") { mainobj.$control.css({ width: mainobj.$control.width() }); } mainobj.togglecontrol(); $('a[href="' + mainobj.anchorkeyword + '"]').click(function() { mainobj.scrollup(); return false; }); $(window).bind("scroll resize", function(e) { mainobj.togglecontrol(); }); }); } }; scrolltotop.init(); </script> </html>