本文实例讲述了jQuery实现的自定义滚动条。分享给大家供大家参考，具体如下：
可以自由的给滚动条定义背景，上下按钮，当然不仅仅是颜色，连图片当背景也可以。支持鼠标滚轮，点击滚动条滚轴定位，上下按钮久按加速，兼容 ie，firefox，chrome。
调用方法：
$("#a").jscroll();
demo：
<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8"/>
<title>demo</title>
<link rel="stylesheet" type="text/css" href="/css/base.min.css" media="all"/>
<style type="text/css">
#a{width:500px;overflow:hidden;position:relative;height:200px;background:#f5f5f5;}
</style>
</head>
<body>
<div id="a">
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>底部</p>
</div>
</body>
</html>
<script type="text/javascript" src="/js/jquery.min.js"></script>
<script type="text/javascript" src="/js/jquery.jscroll.js"></script>
<script type="text/javascript">
$(function(){
$("#a").jscroll();
});
</script>
高级应用（自定义滚动条背景及上下按钮）：
调用图片：
demo：
<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8"/>
<title>demo</title>
<link rel="stylesheet" type="text/css" href="/css/base.min.css" media="all"/>
<style type="text/css">
#a{width:500px;overflow:hidden;position:relative;height:200px;background:#f5f5f5;}
</style>
</head>
<body>
<div id="a">
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>测试文字</p>
<p>底部</p>
</div>
</body>
</html>
<script type="text/javascript" src="/js/jquery.min.js"></script>
<script type="text/javascript" src="/js/jquery.jscroll.js"></script>
<script type="text/javascript">
$(function(){
$("#a").jscroll({
W:"15px", //设置滚动条宽度
BgUrl:"url(/images/s_bg2.gif)", //设置滚动条背景图片地址
Bg:"right 0 repeat-y", //设置滚动条背景图片position,颜色等
Bar:{
Pos:"bottom", //设置滚动条初始化位置在底部
Bd:{ //设置滚动滚轴边框颜色：鼠标离开(默认)，经过
Out:"#a3c3d5",
Hover:"#b7d5e6"
},
Bg:{ //设置滚动条滚轴背景：鼠标离开(默认)，经过，点击
Out:"-45px 0 repeat-y",
Hover:"-58px 0 repeat-y",
Focus:"-71px 0 repeat-y"
}
},
Btn:{
btn:true, //是否显示上下按钮 false为不显示
uBg:{ //设置上按钮背景：鼠标离开(默认)，经过，点击
Out:"0 0",
Hover:"-15px 0",
Focus:"-30px 0"
},
dBg:{ //设置下按钮背景：鼠标离开(默认)，经过，点击
Out:"0 -15px",
Hover:"-15px -15px",
Focus:"-30px -15px"
}
},
Fn:function(){} //滚动时候触发的方法
});
});
</script>
jquery.jscroll.js：
/**
*
* Copyright (c) 2009 May(qq104010230)
* http://www.winwill.com
* http://www.winwill.com/jquery/jscroll.html
* admin@winwill.com
*/
/*--------------------------------------------------------------------------------------------------*/
$.fn.extend({//添加滚轮事件//by jun
mousewheel:function(Func){
return this.each(function(){
var _self = this;
_self.D = 0;//滚动方向
if($.browser.msie||$.browser.safari){
_self.onmousewheel=function(){_self.D = event.wheelDelta;event.returnValue = false;Func && Func.call(_self);};
}else{
_self.addEventListener("DOMMouseScroll",function(e){
_self.D = e.detail>0?-1:1;
e.preventDefault();
Func && Func.call(_self);
},false);
}
});
}
});
$.fn.extend({
jscroll:function(j){
return this.each(function(){
j = j || {}
j.Bar = j.Bar||{};//2级对象
j.Btn = j.Btn||{};//2级对象
j.Bar.Bg = j.Bar.Bg||{};//3级对象
j.Bar.Bd = j.Bar.Bd||{};//3级对象
j.Btn.uBg = j.Btn.uBg||{};//3级对象
j.Btn.dBg = j.Btn.dBg||{};//3级对象
var jun = { W:"15px"
,BgUrl:""
,Bg:"#efefef"
,Bar:{ Pos:"up"
,Bd:{Out:"#b5b5b5",Hover:"#ccc"}
,Bg:{Out:"#fff",Hover:"#fff",Focus:"orange"}}
,Btn:{ btn:true
,uBg:{Out:"#ccc",Hover:"#fff",Focus:"orange"}
,dBg:{Out:"#ccc",Hover:"#fff",Focus:"orange"}}
,Fn:function(){}}
j.W = j.W||jun.W;
j.BgUrl = j.BgUrl||jun.BgUrl;
j.Bg = j.Bg||jun.Bg;
j.Bar.Pos = j.Bar.Pos||jun.Bar.Pos;
j.Bar.Bd.Out = j.Bar.Bd.Out||jun.Bar.Bd.Out;
j.Bar.Bd.Hover = j.Bar.Bd.Hover||jun.Bar.Bd.Hover;
j.Bar.Bg.Out = j.Bar.Bg.Out||jun.Bar.Bg.Out;
j.Bar.Bg.Hover = j.Bar.Bg.Hover||jun.Bar.Bg.Hover;
j.Bar.Bg.Focus = j.Bar.Bg.Focus||jun.Bar.Bg.Focus;
j.Btn.btn = j.Btn.btn!=undefined?j.Btn.btn:jun.Btn.btn;
j.Btn.uBg.Out = j.Btn.uBg.Out||jun.Btn.uBg.Out;
j.Btn.uBg.Hover = j.Btn.uBg.Hover||jun.Btn.uBg.Hover;
j.Btn.uBg.Focus = j.Btn.uBg.Focus||jun.Btn.uBg.Focus;
j.Btn.dBg.Out = j.Btn.dBg.Out||jun.Btn.dBg.Out;
j.Btn.dBg.Hover = j.Btn.dBg.Hover||jun.Btn.dBg.Hover;
j.Btn.dBg.Focus = j.Btn.dBg.Focus||jun.Btn.dBg.Focus;
j.Fn = j.Fn||jun.Fn;
var _self = this;
var Stime,Sp=0,Isup=0;
$(_self).css({overflow:"hidden",position:"relative",padding:"0px"});
var dw = $(_self).width(), dh = $(_self).height()-1;
var sw = j.W ? parseInt(j.W) : 21;
var sl = dw - sw
var bw = j.Btn.btn==true ? sw : 0;
if($(_self).children(".jscroll-c").height()==null){//存在性检测
$(_self).wrapInner("<div class='jscroll-c' style='top:0px;z-index:9999;zoom:1;position:relative'></div>");
$(_self).children(".jscroll-c").prepend("<div style='height:0px;overflow:hidden'></div>");
$(_self).append("<div class='jscroll-e' unselectable='on' style=' height:100%;top:0px;right:0;-moz-user-select:none;position:absolute;overflow:hidden;z-index:10000;'><div class='jscroll-u' style='position:absolute;top:0px;width:100%;left:0;background:blue;overflow:hidden'></div><div class='jscroll-h' unselectable='on' style='background:green;position:absolute;left:0;-moz-user-select:none;border:1px solid'></div><div class='jscroll-d' style='position:absolute;bottom:0px;width:100%;left:0;background:blue;overflow:hidden'></div></div>");
}
var jscrollc = $(_self).children(".jscroll-c");
var jscrolle = $(_self).children(".jscroll-e");
var jscrollh = jscrolle.children(".jscroll-h");
var jscrollu = jscrolle.children(".jscroll-u");
var jscrolld = jscrolle.children(".jscroll-d");
if($.browser.msie){document.execCommand("BackgroundImageCache", false, true);}
jscrollc.css({"padding-right":sw});
jscrolle.css({width:sw,background:j.Bg,"background-image":j.BgUrl});
jscrollh.css({top:bw,background:j.Bar.Bg.Out,"background-image":j.BgUrl,"border-color":j.Bar.Bd.Out,width:sw-2});
jscrollu.css({height:bw,background:j.Btn.uBg.Out,"background-image":j.BgUrl});
jscrolld.css({height:bw,background:j.Btn.dBg.Out,"background-image":j.BgUrl});
jscrollh.hover(function(){if(Isup==0)$(this).css({background:j.Bar.Bg.Hover,"background-image":j.BgUrl,"border-color":j.Bar.Bd.Hover})},function(){if(Isup==0)$(this).css({background:j.Bar.Bg.Out,"background-image":j.BgUrl,"border-color":j.Bar.Bd.Out})})
jscrollu.hover(function(){if(Isup==0)$(this).css({background:j.Btn.uBg.Hover,"background-image":j.BgUrl})},function(){if(Isup==0)$(this).css({background:j.Btn.uBg.Out,"background-image":j.BgUrl})})
jscrolld.hover(function(){if(Isup==0)$(this).css({background:j.Btn.dBg.Hover,"background-image":j.BgUrl})},function(){if(Isup==0)$(this).css({background:j.Btn.dBg.Out,"background-image":j.BgUrl})})
var sch = jscrollc.height();
//var sh = Math.pow(dh,2) / sch ;//Math.pow(x,y)x的y次方
var sh = (dh-2*bw)*dh / sch
if(sh<10){sh=10}
var wh = sh/6//滚动时候跳动幅度
// sh = parseInt(sh);
var curT = 0,allowS=false;
jscrollh.height(sh);
if(sch<=dh){jscrollc.css({padding:0});jscrolle.css({display:"none"})}else{allowS=true;}
if(j.Bar.Pos!="up"){
curT=dh-sh-bw;
setT();
}
jscrollh.bind("mousedown",function(e){
j['Fn'] && j['Fn'].call(_self);
Isup=1;
jscrollh.css({background:j.Bar.Bg.Focus,"background-image":j.BgUrl})
var pageY = e.pageY ,t = parseInt($(this).css("top"));
$(document).mousemove(function(e2){
curT =t e2.pageY - pageY;//pageY浏览器可视区域鼠标位置，screenY屏幕可视区域鼠标位置
setT();
});
$(document).mouseup(function(){
Isup=0;
jscrollh.css({background:j.Bar.Bg.Out,"background-image":j.BgUrl,"border-color":j.Bar.Bd.Out})
$(document).unbind();
});
return false;
});
jscrollu.bind("mousedown",function(e){
j['Fn'] && j['Fn'].call(_self);
Isup=1;
jscrollu.css({background:j.Btn.uBg.Focus,"background-image":j.BgUrl})
_self.timeSetT("u");
$(document).mouseup(function(){
Isup=0;
jscrollu.css({background:j.Btn.uBg.Out,"background-image":j.BgUrl})
$(document).unbind();
clearTimeout(Stime);
Sp=0;
});
return false;
});
jscrolld.bind("mousedown",function(e){
j['Fn'] && j['Fn'].call(_self);
Isup=1;
jscrolld.css({background:j.Btn.dBg.Focus,"background-image":j.BgUrl})
_self.timeSetT("d");
$(document).mouseup(function(){
Isup=0;
jscrolld.css({background:j.Btn.dBg.Out,"background-image":j.BgUrl})
$(document).unbind();
clearTimeout(Stime);
Sp=0;
});
return false;
});
_self.timeSetT = function(d){
var self=this;
if(d=="u"){curT-=wh;}else{curT =wh;}
setT();
Sp =2;
var t =500 - Sp*50;
if(t<=0){t=0};
Stime = setTimeout(function(){self.timeSetT(d);},t);
}
jscrolle.bind("mousedown",function(e){
j['Fn'] && j['Fn'].call(_self);
curT = curT e.pageY - jscrollh.offset().top - sh/2;
asetT();
return false;
});
function asetT(){
if(curT<bw){curT=bw;}
if(curT>dh-sh-bw){curT=dh-sh-bw;}
jscrollh.stop().animate({top:curT},100);
var scT = -((curT-bw)*sch/(dh-2*bw));
jscrollc.stop().animate({top:scT},1000);
};
function setT(){
if(curT<bw){curT=bw;}
if(curT>dh-sh-bw){curT=dh-sh-bw;}
jscrollh.css({top:curT});
var scT = -((curT-bw)*sch/(dh-2*bw));
jscrollc.css({top:scT});
};
$(_self).mousewheel(function(){
if(allowS!=true) return;
j['Fn'] && j['Fn'].call(_self);
if(this.D>0){curT-=wh;}else{curT =wh;};
setT();
})
});
}
});
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