js实现淘宝首页图片轮播效果

时间:2024-09-22 16:34:38

原文:http://ce.sysu.edu.cn/hope2008/Education/ShowArticle.asp?ArticleID=10585

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>淘宝首页图片轮播效果</title>
<style>
<!--
* {margin: 0;padding:0;}
body {background: #222;}
ol {list-style: none;}
img {border: 0 none;}
#slider {
border: 1px solid #F60;
width: 490px;
height: 170px;
overflow: hidden;
position: relative;
margin: 2em auto;
}
#slider .player {
/*width: 2450px;
height: 850px;*/
position: absolute;
top: 0px;
left: 0px;
}
#slider .player li {
width: 490px;
height: 170px;
}
#slider .btns {
position: absolute;
right: 10px;
bottom: 5px;
height: 30px;
}
#slider .btns li {
font: 13px Tahoma, Arial, 宋体, sans-serif;
float: left;
margin: 0 3px;
border: 1px solid #F60;
background-color: #FFF;
color: #CC937A;
opacity: .8;
cursor: pointer;
width: 20px;
height: 20px;
line-height: 19px;
text-align: center;
-moz-border-radius: 10px;
-webkit-border-radius: 10px;
border-radius: 10px;
}
#slider .btns li.active {
background: #F60;
color: #FFF;
font-weight: bold;
opacity: 1;
}
-->
</style>
<script>
//<![CDATA[
function $(id) {
return document.getElementById(id);
};
function getByClass(className, context) {
/*
* 功能说明:
* 传入类名、节点名(默认document),获取context下类名为classNa的节点
*/
context = context || document;
if(context.getElementsByClassName) {
return context.getElementsByClassName(className);
} else {
var nodes = [];
var tags = context.getElementsByTagName('*');
for(var i=0, len=tags.length; i<len; i++) {
if(hasClass(tags[i], className)) {
nodes.push(tags[i]);
}
}
return nodes;
}
}
function hasClass(node, className) {
/*
* 功能说明:
* 传入节点及一个类名,检查该节点是否含有传入的类名
*/
var names = node.className.split(/\s+/);
for(var i=0, len=names.length; i<len; i++) {
if(names[i] == className) {
return true;
}
}
return false;
}
function animate(o,start,alter,dur,fx) {
/*
* 功能说明:
* 设置动画
* o:要设置动画的对象
* start:开始的对象
* alter:总的对象
* dur:动画持续多长时间
* fx:动画类型
*/
var curTime=0;
var t=setInterval(function () {
if (curTime>=dur) clearInterval(t);
for (var i in start) {
o.style[i]=fx(start[i],alter[i],curTime,dur)+"px";
}
curTime+=40;
},40);
return function () {
clearInterval(t);
};
}
var Tween = {
/*
* 功能说明:
* 加速运动
* curTime:当前时间,即动画已经进行了多长时间,开始时间为0
* start:开始值
* alter:总的变化量
* dur:动画持续多长时间
*/
Linear:function (start,alter,curTime,dur) {return start+curTime/dur*alter;},//最简单的线性变化,即匀速运动
Quad:{//二次方缓动
easeIn:function (start,alter,curTime,dur) {
return start+Math.pow(curTime/dur,2)*alter;
},
easeOut:function (start,alter,curTime,dur) {
var progress =curTime/dur;
return start-(Math.pow(progress,2)-2*progress)*alter;
},
easeInOut:function (start,alter,curTime,dur) {
var progress =curTime/dur*2;
return (progress<1?Math.pow(progress,2):-((--progress)*(progress-2) - 1))*alter/2+start;
}
},
};
function Player(btns, scrollContent, imgHeight, timeout, hoverClass) {
/*
* btns:按钮,类型是数组
* scrollContent:摇滚动的块,一个DOM对象,这里是ol
* imgHeight:每一张图片的高度,当然,如果想改成左右滚动,这里传入每一张图片的宽,唯一需要注意的是每一张图片宽高必须相同,图片数量可调整
* timeout:切换速度快慢,默认为1.5ms
* hoverClass:每一个按钮激活时的类名
*/
hoverClass = hoverClass || 'active';
timeout = timeout || 1500;
this.btns = btns;
this.scrollContent = scrollContent;
this.hoverClass = hoverClass;
this.timeout = timeout;
this.imgHeight = imgHeight;
var _this = this;
for(var i=0; i<btns.length; i++) {
this.btns[i].index = i;
btns[i].onmouseover = function() {
_this.stop();
_this.invoke(this.index);
}
btns[i].onmouseout = function() {
_this.start();
}
}
this.invoke(0);
}
Player.prototype = {
constructor : Player,
start : function() {
var _this = this;
this.stop();
this.intervalId = setInterval(function() {
_this.next();
}, this.timeout);
},
stop: function() {
clearInterval(this.intervalId);
},
invoke: function(n) {
this.pointer = n;
if(this.pointer >= this.btns.length) {
this.pointer = 0;
}
this.clearHover();
this.btns[this.pointer].className = this.hoverClass;
//this.scrollContent.style.top = parseInt(-this.imgHeight * this.pointer) + 'px';
var startVal = parseInt(this.scrollContent.style.top) || 0;
var alterVal = (parseInt(-startVal - this.imgHeight * this.pointer));
this.animateIterval && this.animateIterval();//修正快速切换时闪动
this.animateIterval=animate(this.scrollContent, {top : startVal},{top : alterVal}, 1000, Tween.Quad.easeOut);
//这里默认设置每张图滚动的总时间是1s
},
next: function() {
this.invoke(this.pointer + 1);
},
clearHover: function() {
for(var i=0; i<this.btns.length; i++) {
this.btns[i].className = '';
};
}
}
window.onload = function() {
var btns = getByClass('btns', $('slider'))[0].getElementsByTagName('li');
var player = getByClass('player', $('slider'))[0];
var player = new Player(btns, player, 170, 1500, undefined);
player.start();
//player.invoke(2);
}
//]]>
</script>
</head>
<body>
<div id="slider">
<ol class="player">
<li><a href=""><img src="/hope2008/Education/UploadFiles_5303/201103/20110304195203607.gif" alt="1" /></a></li>
<li><a href=""><img src="/hope2008/Education/UploadFiles_5303/201103/20110304195203167.jpg" alt="2" /></a></li>
<li><a href=""><img src="/hope2008/Education/UploadFiles_5303/201103/20110304195204315.jpg" alt="3" /></a></li>
<li><a href=""><img src="/hope2008/Education/UploadFiles_5303/201103/20110304195204559.jpg" alt="4" /></a></li>
<li><a href=""><img src="/hope2008/Education/UploadFiles_5303/201103/20110304195204728.jpg" alt="5" /></a></li>
</ol>
<ol class="btns">
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
</ol>
</div>
</body>
</html>