自动显隐回到顶部javascript代码

当拖动网页滚动条的时,页面右下角会自动出现“回到顶部”的图标,点击该图标就可以回到顶部!此代码原理是当页面到达非第一屏时,即显示TOP图标,点击后页面平滑滚动到第一屏!效果很爽!

自动显隐回到顶部代码

将如下内容直接保存为 scrolltopcontrol.js ,直接在页面调用即可,代码中的 up.png 图片为向上箭头,可自己替换。

//** jQuery Scroll to Top Control script- (c) Dynamic Drive DHTML code library: http://www.dynamicdrive.com.

var scrolltotop={
	//startline: Integer. Number of pixels from top of doc scrollbar is scrolled before showing control
	//scrollto: Keyword (Integer, or "Scroll_to_Element_ID"). How far to scroll document up when control is clicked on (0=top).
	setting: {startline:100, scrollto: 0, scrollduration:1000, fadeduration:[500, 100]},
	controlHTML: '<img src="up.png" style="width:24px; height:24px" />', //HTML for control, which is auto wrapped in DIV w/ ID="topcontrol"
	controlattrs: {offsetx:5, offsety:5}, //offset of control relative to right/ bottom of window corner
	anchorkeyword: '#top', //Enter href value of HTML anchors on the page that should also act as "Scroll Up" links

	state: {isvisible:false, shouldvisible:false},

	scrollup:function(){
		if (!this.cssfixedsupport) //if control is positioned using JavaScript
			this.$control.css({opacity:0}) //hide control immediately after clicking it
		var dest=isNaN(this.setting.scrollto)? this.setting.scrollto : parseInt(this.setting.scrollto)
		if (typeof dest=="string" && jQuery('#'+dest).length==1) //check element set by string exists
			dest=jQuery('#'+dest).offset().top
		else
			dest=0
		this.$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($){
			var mainobj=scrolltotop
			var iebrws=document.all
			mainobj.cssfixedsupport=!iebrws || iebrws && document.compatMode=="CSS1Compat" && window.XMLHttpRequest //not IE or IE7+ browsers in standards mode
			mainobj.$body=(window.opera)? (document.compatMode=="CSS1Compat"? $('html') : $('body')) : $('html,body')
			mainobj.$control=$('<div id="topcontrol">'+mainobj.controlHTML+'</div>')
				.css({position:mainobj.cssfixedsupport? 'fixed' : 'absolute', bottom:mainobj.controlattrs.offsety, right:mainobj.controlattrs.offsetx, opacity:0, cursor:'pointer'})
				.attr({title:'Scroll Back to Top'})
				.click(function(){mainobj.scrollup(); return false})
				.appendTo('body')
			if (document.all && !window.XMLHttpRequest && mainobj.$control.text()!='') //loose check for IE6 and below, plus whether control contains any text
				mainobj.$control.css({width:mainobj.$control.width()}) //IE6- seems to require an explicit width on a DIV containing text
			mainobj.togglecontrol()
			$('a[href="' + mainobj.anchorkeyword +'"]').click(function(){
				mainobj.scrollup()
				return false
			})
			$(window).bind('scroll resize', function(e){
				mainobj.togglecontrol()
			})
		})
	}
}

scrolltotop.init()

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    8年前 (2011-06-26)
    回复
  • Ellis Whelehan

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    8年前 (2011-02-23)
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  • Jeanette

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    8年前 (2011-01-28)
    回复
    回复Jeanette
  • godaddy

    这个不错!

    8年前 (2011-01-21)
    回复
    回复godaddy
  • lenen

    kkqkvbakaaqnlcmehiflgscgecgbjbqc

    8年前 (2011-01-19)
    回复
    回复lenen
  • weddingdresses

    呵呵最后谢谢博主

    9年前 (2010-10-20)
    回复
  • weddingdress

    呵呵 很喜欢这个代码功能

    9年前 (2010-10-20)
    回复
    回复weddingdress
  • nikeforce

    谢谢楼主的分享,我也用用呢

    9年前 (2010-09-26)
    回复
    回复nikeforce
  • uggbootsonsale

    博主你太好了 我也下载个!

    9年前 (2010-09-20)
    回复
  • uggboots

    有了这个就方便多了!

    nuodou 于 2010-9-2 11:10:37 回复

    大家方便才是真的方便

    9年前 (2010-09-01)
    回复
    回复uggboots
  • 淘宝最好的减肥药

    这个小代码功能感觉很人性化,值得推荐

    9年前 (2010-08-28)
    回复
  • 画英雄

    用360浏览器会被当成网页广告过滤掉。这个比较麻烦!

    nuodou 于 2010-8-13 9:42:45 回复

    我这边默认设置是可以显示的!你是不是手动设置高拦截啊?

    9年前 (2010-08-12)
    回复
    回复画英雄
  • 雨像眼泪

    看见你恢复我也很高兴,默默支持你

    nuodou 于 2010-8-11 10:15:08 回复

    多谢哥们支持

    9年前 (2010-08-07)
    回复
    回复雨像眼泪
  • diyidu

    你这博客是什么程序内核?感觉怪怪的。这个不错,下载收藏。

    nuodou 于 2010-8-6 12:53:26 回复

    哈哈!怎么怪了?

    9年前 (2010-08-06)
    回复
    回复diyidu
  • 土狼妹妹

    这个功能可以试试,不错

    9年前 (2010-08-05)
    回复
    回复土狼妹妹
  • 飞晏

    回来了~~ 开始更新了!!

    nuodou 于 2010-8-4 9:45:02 回复

    是啊!心情慢慢恢复!失去亲人的伤真的很痛啊!

    9年前 (2010-08-03)
    回复
    回复飞晏
  • 祛痘产品哪种好

    那个放大镜非常的不错啊!
    谢谢,博主分享!

    nuodou 于 2010-8-4 9:46:16 回复

    愿生意兴隆!哈哈!

    9年前 (2010-08-03)
    回复
  • 减肥药排行榜

    沙发,
    谢谢,博主分享。
    这代码非常不错啊!

    nuodou 于 2010-8-4 9:46:42 回复

    自己代理的还是投放别人的?

    9年前 (2010-08-03)
    回复