1 <script src="jquery-1.11.3.min.js"></script> 2 <script> 3 (function($){ 4 function Obj(element,options){ 5 this.element = element; 6 this.defaults = { 7 time:30, 8 speed:8, 9 scrollTop:100 10 }; 11 this.options = $.extend({},this.defaults,options) 12 } 13 Obj.prototype.toTop = function(){ 14 var options = $.extend({},this.defaults,options); 15 var timer = null; 16 $("body").append($("<span id='toTop' style='position: fixed;width: 54px;height: 54px;bottom: 50px;right: 70px;cursor: pointer;background: red; z-Index: 101;display:none'></span>")); 17 $("#toTop").bind("click",function(){ 18 clearInterval(timer); 19 timer = setInterval(function(){ 20 var scrollTop = document.documentElement.scrollTop || document.body.scrollTop; 21 var iSpeed = Math.floor(0-scrollTop/options.speed); 22 document.documentElement.scrollTop = document.body.scrollTop = scrollTop + iSpeed; 23 if(scrollTop == 0){ 24 clearInterval(timer); 25 } 26 },options.time); 27 }); 28 return this; 29 }; 30 Obj.prototype.scroll = function(){ 31 var options = $.extend({},this.defaults,options); 32 this.element.bind("scroll",function(){ 33 var scrollTop = document.documentElement.scrollTop || document.body.scrollTop; 34 if(scrollTop>=options.scrollTop){ 35 $("#toTop").fadeIn(); 36 }else{ 37 $("#toTop").fadeOut(); 38 } 39 }) 40 return this; 41 } 42 $.prototype.extend({ 43 "toTop":function(options){ 44 var toTop = new Obj(this,options); 45 return toTop.toTop() 46 }, 47 "scroll":function(options){ 48 var scroll = new Obj(this,options); 49 return scroll.scroll() 50 } 51 }) 52 })(jQuery) 53 54 $(function(){ 55 $("#toTop").toTop({ 56 time:30, 57 speed:8 58 }); 59 $(window).scroll({ 60 scrollTop:100 61 }); 62 }) 63 </script>
