效果如下：
all code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8"/>
<title>图片轮播切换效果</title>
<style>
#banner {position:relative; width:478px; height:286px; border:1px solid #666; overflow:hidden;margin:0 auto;}
#banner_list img {border:0px;}
#banner_bg {position:absolute; bottom:0;background-color:#000;height:30px;filter: Alpha(Opacity=30);opacity:0.3;z-index:1000;cursor:pointer; width:478px; }
#banner_info{position:absolute; bottom:0; left:5px; line-height:30px;color:#fff;z-index:1001}
#banner_text {position:absolute;width:120px;z-index:1002; right:3px; bottom:3px;}
#banner ul {position:absolute;list-style-type:none;filter: Alpha(Opacity=75);opacity:0.75; border:1px solid #fff;z-index:1002;margin:0; padding:0; bottom:3px; right:5px;}
#banner ul li { padding:0px 8px;float:left;display:block;color:#FFF;border:#fff 1px solid;background-color:#6f4f67;cursor:pointer}
#banner ul li.on{ background-color:#900}
#banner_list a{position:absolute;} /*<!-- 让四张图片都可以重叠在一起-->*/
</style>
</head>
<body>
<div id="banner">
<div id="banner_bg"></div> <!--标题背景-->
<a href="#" id="banner_info"></a> <!--标题-->
<ul id="list"></ul>
<div id="banner_list">
<a href="#" target="_blank"><img src="imgs/p1.jpg" /></a>
<a href="#" target="_blank"><img src="imgs/p5.jpg" /></a>
<a href="#" target="_blank"><img src="imgs/p3.jpg" /></a>
<a href="#" target="_blank"><img src="imgs/p4.jpg" /></a>
</div>
</div>
</body>
</html>
<script>
/**************************************************
* 用法：//count:图片数量，wrapId:包裹图片的DIV,ulId:按
钮DIV,infoId：信息栏 babyzone.scroll(count,wrapId,ulId,infoId);
**************************************************/
var babyzone = function() {
function id(name) {return document.getElementById(name);}
//遍历函数
function each(arr, callback, thisp) {
if (arr.forEach) {arr.forEach(callback, thisp);}
else { for (var i = 0, len = arr.length; i < len; i++) callback.call(thisp, arr[i], i, arr);}
}
function fadeIn(elem) {
setOpacity(elem, 0)
for ( var i = 0; i < 20; i++) {
(function() {
var pos = i * 5;
setTimeout(function() {
setOpacity(elem, pos)
}, i * 25);
})(i);
}
}
function fadeOut(elem) {
for ( var i = 0; i <= 20; i++) {
(function() {
var pos = 100 - i * 5;
setTimeout(function() {
setOpacity(elem, pos)
}, i * 25);
})(i);
}
}
// 设置透明度
function setOpacity(elem, level) {
if (elem.filters) {
elem.style.filter = "alpha(opacity=" + level + ")";
} else {
elem.style.opacity = level / 100;
}
}
return {
//count:图片数量，wrapId:包裹图片的DIV,ulId:按钮DIV, infoId：信息栏
scroll : function(count,wrapId,ulId,infoId) {
var self=this;
var targetIdx=0; //目标图片序号
var curIndex=0; //现在图片序号
//添加Li按钮
var frag=document.createDocumentFragment();
this.num=[]; //存储各个li的应用，为下面的添加事件做准备
this.info=id(infoId);
for(var i=0;i<count;i++){
(this.num[i]=frag.appendChild(document.createElement("li"))).innerHTML=i+1;
}
id(ulId).appendChild(frag);
//初始化信息
this.img = id(wrapId).getElementsByTagName("a");
this.info.innerHTML=self.img[0].firstChild.title;
this.num[0].className="on";
//将除了第一张外的所有图片设置为透明
each(this.img,function(elem,idx,arr){
if (idx!=0) setOpacity(elem,0);
});
//为所有的li添加点击事件
each(this.num,function(elem,idx,arr){
elem.onclick=function(){
self.fade(idx,curIndex);
curIndex=idx;
targetIdx=idx;
}
});
//自动轮播效果
var itv=setInterval(function(){
if(targetIdx<self.num.length-1){
targetIdx++;
}else{
targetIdx=0;
}
self.fade(targetIdx,curIndex);
curIndex=targetIdx;
},2000);
id(ulId).onmouseover=function(){ clearInterval(itv)};
id(ulId).onmouseout=function(){
itv=setInterval(function(){
if(targetIdx<self.num.length-1){
targetIdx++;
}else{
targetIdx=0;
}
self.fade(targetIdx,curIndex);
curIndex=targetIdx;
},2000);
}
},
fade:function(idx,lastIdx){
if(idx==lastIdx) return;
var self=this;
fadeOut(self.img[lastIdx]);
fadeIn(self.img[idx]);
each(self.num,function(elem,elemidx,arr){
if (elemidx!=idx) {
self.num[elemidx].className='';
}else{
id("list").style.background="";
self.num[elemidx].className='on';
}
});
this.info.innerHTML=self.img[idx].firstChild.title;
}
}
}();
babyzone.scroll(4,"banner_list","list","banner_info");
</script>