js写的简单轮播图
这个轮播图代码是从网上找来的，专门找了个写法简单的，只是作为一个小练习，大概原理如下：
1.首先是图片切换
2.自动播放
3.调用自动播放
4.移动到容器上边停止播放，离开自动播放
5.移动到导航上停止播放，离开自动播放
6.移动到导航上，切换相对应的导航
然后贴代码：
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
*{margin:0;
padding:0;
list-style:none;}
.wrap{height:170px;
490px;
margin:60px auto;
overflow: hidden;
position: relative;
margin:100px auto;}
.wrap ul{position:absolute;}
.wrap ul li{height:170px;}
.wrap ol{position:absolute;
right:5px;
bottom:10px;}
.wrap ol li{height:20px; 20px;
background:#ccc;
border:solid 1px #666;
margin-left:5px;
color:#000;
float:left;
line-height:center;
text-align:center;
cursor:pointer;}
.wrap ol .on{background:#E97305;
color:#fff;}
</style>
<script type="text/javascript">
window.onload=function(){
var wrap=document.getElementById('wrap'),
pic=document.getElementById('pic').getElementsByTagName("li"),
list=document.getElementById('list').getElementsByTagName('li'),
index=0,
timer=null;
// 定义并调用自动播放函数
timer = setInterval(autoPlay, 2000);
// 鼠标划过整个容器时停止自动播放
wrap.onmouseover = function () {
clearInterval(timer);
}
// 鼠标离开整个容器时继续播放至下一张
wrap.onmouseout = function () {
timer = setInterval(autoPlay, 2000);
}
// 遍历所有数字导航实现划过切换至对应的图片
for (var i = 0; i < list.length; i++) {
list[i].onmouseover = function () {
clearInterval(timer);
index = this.innerText - 1;
changePic(index);
};
};
function autoPlay () {
if (++index >= pic.length) index = 0;
changePic(index);
}
// 定义图片切换函数
function changePic (curIndex) {
for (var i = 0; i < pic.length; ++i) {
pic[i].style.display = "none";
list[i].className = "";
}
pic[curIndex].style.display = "block";
list[curIndex].className = "on";
}
};
</script>
</head>
<body>
<div class="wrap" id='wrap'>
<ul id="pic">
<li><img src="http://img.mukewang.com/54111cd9000174cd04900170.jpg" alt=""></li>
<li><img src="http://img.mukewang.com/54111dac000118af04900170.jpg" alt=""></li>
<li><img src="http://img.mukewang.com/54111d9c0001998204900170.jpg" alt=""></li>
<li><img src="http://img.mukewang.com/54111d8a0001f41704900170.jpg" alt=""></li>
<li><img src="http://img.mukewang.com/54111d7d00018ba604900170.jpg" alt=""></li>
</ul>
<ol id="list">
<li class="on">1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
</ol>
</div>
</body>
</html>