用JS实现图片轮播效果代码（一）

<div id="content"> <!-- 总的父容器 -->
<div class="carousel-inner"> <!-- 包含图片的容器 -->
<div class="item "><img src="./img/lunbo1.jpg" alt="第一张图片"></div>
<div class="item"><img src="./img/lunbo2.jpg" alt="第二张图片"></div>
<div class="item"><img src="./img/lunbo3.jpg" alt="第三张图片"></div>
</div>
<!-- 图片下方的指示圆圈-->
<ul class="carousel-indicators">
<li id='pic1'>●</li>
<li id='pic2'>●</li>
<li id='pic3'>●</li>
</ul>
<!-- 图片左右方来回滚动图片的左右箭头-->
<a href="#" class="carousel-control prev"><span><</span></a>
<a href="#" class="carousel-control next"><span>></span></a>
</div>

#content{
width: 100%;
height:500px;
position: relative;
}
.carousel-inner{
position: relative;
width: 100%;
overflow: hidden; 
height:500px; 
}
.carousel-inner>.item>img{
display: block; 
line-height: 1; 
z-index: 1;
}
.carousel-indicators{
position: absolute;
bottom:10px;
left:45%;
z-index: 2;
list-style-type: none;
}
.carousel-indicators li{
display:inline-block;
padding: 0 15px;
font-size: 24px;
color:#999; 
cursor: pointer;
z-index: 2;
}
.active1{
font-size: 28px;
color:#fff;
}
.carousel-control{
position: absolute;
text-decoration:none;
color: #999;
font-weight: bold;
opacity: .5;
font-size: 40px;
z-index: 3;
}
.carousel-control:hover{
color:fff;
text-decoration: none;
opacity: .9;
outline: none;
font-size: 42px;
}
.prev{
top: 30%; 
left:20px; 
}
.next{
top:30%;
right: 20px;
}

window.onload = function(){
//轮播初始化
var lunbo = document.getElementById('content');
var imgs = lunbo.getElementsByTagName('img'); 
var uls = lunbo.getElementsByTagName('ul');
var lis = lunbo.getElementsByTagName('li');
//初始状态下，一个圆圈为高亮模式
lis[0].style.fontSize = '26px';
lis[0].style.color = '#fff';
//定义一个全局变量，用来进行自动轮播图片顺序的变化
var pic_index = 1;
//自动轮播.使用pic_time记录播放，可以随时使用clearInterval()清除掉。
var pic_time = setInterval(autobofang,3000);
//手动轮播
for(var i=0;i<lis.length;i++){ 
lis[i].addEventListener("mouseover",change,false);
}
function change(event){ 
var event=event||window.event;
var target=event.target||event.srcElement; 
var children = target.parentNode.children; 
for(var i=0;i<children.length;i++){
if(target == children[i]){ 
picChange(i); 
} 
}
} 
//图片切换函数
function picChange(i){ 
//让所有图片都不显示，所有圆圈都为普通样式 
for(var j=0;j<imgs.length;j++){
imgs[j].style.display = 'none'; lis[j].style.fontSize = '24px';
lis[j].style.color = '#999';
}
//让选中的索引的图片显示，对应的圆圈高亮 
imgs[i].style.display = 'block'; 
lis[i].style.fontSize = '26px';
lis[i].style.color = '#fff'; 
}
//自动播放的事件处理
function autobofang(){
if(pic_index >= lis.length){
pic_index = 0;
}
change1(pic_index);
pic_index++;
}
//自动播放的图片转化中的事件
function change1(index){ 
picChange(index);
//鼠标移入ul标签，自动播放图片暂停
uls[0].addEventListener("mouseover",pause,false);
//鼠标移出ul标签，自动播放图片继续
uls[0].addEventListener("mouseout",go,false);
}
//自动播放暂停函数
function pause(event){
var event=event||window.event;
var target=event.target||event.srcElement;
switch(target.id){
case "pic1":
clearInterval(pic_time); 
break;
case "pic2":
clearInterval(pic_time);
break;
case "pic3":
clearInterval(pic_time);
break;
}
}
//自动播放图片继续函数
function go(event){
var event=event||window.event;
var target=event.target||event.srcElement; 
switch(target.id){
case "pic1":
pic_index = 1; 
pic_time = setInterval(autobofang,3000);
break;
case "pic2":
pic_index = 2; 
pic_time = setInterval(autobofang,3000);
break;
case "pic3":
pic_index = 3; 
pic_time = setInterval(autobofang,3000); 
break;
}
}
}