<!doctype html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>轮播图</title>
<style type="text/css">
*{ padding:0; margin:0; list-style:none; border:0;}
.all{
width:500px;
height:200px;
padding:7px;
border:1px solid #ccc;
margin:100px auto;
position:relative;
}
.screen{
width:500px;
height:200px;
overflow:hidden;
position:relative;
}
.screen li{ width:500px; height:200px; overflow:hidden; float:left;}
.screen ul{ position:absolute; left:0; top:0px; width:3000px;}
.all ol{ position:absolute; right:10px; bottom:10px; line-height:20px; text-align:center;}
.all ol li{ float:left; width:20px; height:20px; background:#fff; border:1px solid #ccc; margin-left:10px; cursor:pointer;}
.all ol li.current{ background:yellow;}
#arr {display: none;}
#arr span{ width:40px; height:40px; position:absolute; left:5px; top:50%; margin-top:-20px; background:#000; cursor:pointer; line-height:40px; text-align:center; font-weight:bold; font-family:'黑体'; font-size:30px; color:#fff; opacity:0.3; border:1px solid #fff;}
#arr #right{right:5px; left:auto;}
</style>
<script>
window.onload = function () {
//需求：无缝滚动。
//思路：赋值第一张图片放到ul的最后，然后当图片切换到第五张的时候
// 直接切换第六章，再次从第一张切换到第二张的时候先瞬间切换到
// 第一张图片，然后滑动到第二张
//步骤：
//1.获取事件源及相关元素。（老三步）
//2.复制第一张图片所在的li,添加到ul的最后面。
//3.给ol中添加li，ul中的个数-1个，并点亮第一个按钮。
//4.鼠标放到ol的li上切换图片
//5.添加定时器
//6.左右切换图片（鼠标放上去隐藏，移开显示）
var screen = document.getElementById("screen");
var ul = screen.children[0];
var ol = screen.children[1];
var div = screen.children[2];
var imgWidth = screen.offsetWidth;
//2
var tempLi = ul.children[0].cloneNode(true);
ul.appendChild(tempLi);
//3
for(var i = 0; i < ul.children.length - 1; i++) {
var newOlLi = document.createElement("li");
newOlLi.innerHTML = i + 1;
ol.appendChild(newOlLi);
}
var olLiArr = ol.children;
olLiArr[0].className = "current";
//4
for(var i = 0, len = olLiArr.length; i < len; i++) {
olLiArr[i].index = i;
olLiArr[i].onmouseover = function (ev) {
for(var j = 0; j < len; j++) {
olLiArr[j].className = "";
}
this.className = "current";
key = square = this.index;
animate(ul, -this.index * imgWidth);
}
}
//5
var key = 0;
var square = 0;
var timer = setInterval(autoPlay, 1000);
screen.onmouseover = function (ev) {
clearInterval(timer);
div.style.display = "block";
}
screen.onmouseout = function (ev) {
timer = setInterval(autoPlay, 1000);
div.style.display = "none";
}
//6
var divArr = div.children;
divArr[0].onclick = function (ev) {
key--;
if(key < 0) {
ul.style.left = -(ul.children.length-1) * imgWidth + "px";
key = 4;
}
animate(ul, -key * imgWidth);
square--;
if(square < 0) {
square = 4;
}
for(var k = 0; k < len; k++) {
olLiArr[k].className = "";
}
olLiArr[square].className = "current";
}
divArr[1].onclick = autoPlay;
function autoPlay() {
key++;
//当不满足下面的条件是时候，轮播图到了最后一个孩子，进入条件中后，瞬移到
//第一张，继续滚动。
if(key > ul.children.length - 1) {
ul.style.left = 0;
key = 1;
}
animate(ul, -key * imgWidth);
square++;
if(square > 4) {
square = 0;
}
for(var k = 0; k < len; k++) {
olLiArr[k].className = "";
}
olLiArr[square].className = "current";
}
function animate(ele,target){
clearInterval(ele.timer);
var speed = target>ele.offsetLeft?10:-10;
ele.timer = setInterval(function () {
var val = target - ele.offsetLeft;
ele.style.left = ele.offsetLeft + speed + "px";
if(Math.abs(val)<Math.abs(speed)){
ele.style.left = target + "px";
clearInterval(ele.timer);
}
},10)
}
}
</script>
</head>
<body>
<div class="all" id='all'>
<div class="screen" id="screen">
<ul id="ul">
<li><img src="images1.jpg" width="500" height="200" /></li>
<li><img src="images2.jpg" width="500" height="200" /></li>
<li><img src="images3.jpg" width="500" height="200" /></li>
<li><img src="images4.jpg" width="500" height="200" /></li>
<li><img src="images5.jpg" width="500" height="200" /></li>
</ul>
<ol>
</ol>
<div id="arr">
<span id="left"><</span>
<span id="right">></span>
</div>
</div>
</div>
</body>
</html>
