html和css就不详细说明了,也是简单布局,通过定位把跟随图片的小框,定位到图片下方
<!DOCTYPE html>
<html> <head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
* {
margin: 0;
padding: 0;
font-size: 12px;
} .photo {
width: 400px;
height: 200px;
margin: 50px;
position: relative;
} .main {
width: 400px;
height: 200px;
position: relative;
} .main1 li {
width: 400px;
height: 200px;
list-style-type: none;
} .pto {
position: absolute;
left: 0;
top: 0;
} .pto1 {
width: 400px;
height: 200px;
background: red;
} .pto2 {
width: 400px;
height: 200px;
background: pink;
display: none;
} .pto3 {
width: 400px;
height: 200px;
background: blue;
display: none;
} .btn {
width: 30px;
height: 30px;
position: absolute;
} .btn1 {
left: 0;
top: 85px;
background: url("img/left.png");
} .btn2 {
right: 0;
top: 85px;
background: url("img/right.png");
} .circleBtn {
position: absolute;
top: 170px;
right: 182px;
width: 42px;
height: 10px;
zoom: 1;
} .circleBtn span {
width: 10px;
height: 10px;
margin: 0 2px;
float: left;
cursor: pointer;
background: url("img/cir.png");
} .circleBtn .light {
background: url("img/oncir.gif");
}
</style>
<script type="text/javascript" src="jiaodiantujs.js">
</script> </head> <body>
<div class="photo" id="main">
<div class="main">
<ul class="main1" id="amain">
<li class="pto pto1">one</li>
<li class="pto pto2">two</li>
<li class="pto pto3">three</li>
</ul>
</div>
<!--
<span class="btn btn1" id="btn1"></span>
<span class="btn btn2" id="btn2"></span>
-->
<div class="circleBtn" id="circleBtn">
<span class="light"></span>
<span></span>
<span></span>
</div> </div>
</body> </html>
下面是javacript部分
function $(id) {
return typeof id === "string" ? document.getElementById(id) : id;
}
window.onload = function() {
//pto变量为所展示的图片集和
var pto = $("amain").getElementsByTagName("li");
//定义一个span标签的集合cirBtn
var cirBtn = $("circleBtn").getElementsByTagName("span");
//定义一个全局变量
var index = 0;
//定义一个setInterval方法cirTimer
var cirTimer = null;
for (var i = 0; i < cirBtn.length; i++) {
//给图片加上id=0,1,2
cirBtn[i].id = i;
//鼠标移动邦定触发事件:显示当前id对应的图片
cirBtn[i].onmouseenter = function() {
//先停止自动循环
clearInterval(cirTimer);
//隐藏图片和小框
clearBtn();
//显示当前id对应的图片和小框
showBtn(this.id);
}
//鼠标离开触发事件:自动循环
cirBtn[i].onmouseout = function() {
cirTimer = setInterval(autoPlay, 2000);
}
}
//设置当前只有一个定时器cirTimer
if (cirTimer) {
clearInterval(cirTimer);
cirTimer = null;
}
cirTimer = setInterval(autoPlay, 2000);
//自动循环函数
function autoPlay() {
//当index小于2则++,否则就是超过长度,则归0即index=0
if (index < cirBtn.length - 1) {
index++;
} else {
index = 0;
}
//console.log(index);
//清除函数
clearBtn();
//显示函数
showBtn(index);
}
//定义一个隐藏图片和小框的函数
function clearBtn() {
for (var i = 0; i < cirBtn.length; i++) {
cirBtn[i].className = "";
pto[i].style.display = "none";
}
}
//定义一个显示当前id对应的图片和小框的函数
function showBtn(x) {
for (var i = 0; i < cirBtn.length; i++) {
console.log(x);
if (i == x) {
cirBtn[i].className = "light";
pto[i].style.display = "block";
}
//这里重要了.这里把x赋值给index是为了让循环从停止的id重新开始循环
index = x;
}
}
}