<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>幻灯片切换效果</title>
<style>
p {margin: 0;}
body {text-align: center;}
#box {width: 400px; height: 400px; border: 10px solid #ccc; margin: 50px auto 0; position: relative;}
a {width: 40px; height: 40px; background: #fff; filter: alpha(opacity: 80); opacity: 0.8; position: absolute; top: 160px;
font-size: 18px; color: #000; text-align: center; line-height: 40px; text-decoration: none;}
a:hover {filter: alpha(opacity: 30); opacity: 0.3;}
#prev {left: 10px;}
#next {right: 10px;}
#p1 {width: 400px; height: 30px; line-height: 30px; text-align: center; background: #000;
color: #fff; font-size: 14px; filter: alpha(opacity: 80); opacity: 0.8; position: absolute; bottom: 0; left: 0;}
strong {width: 400px; height: 30px; line-height: 30px; text-align: center; background: #000; color: #fff;
font-size: 14px; filter: alpha(opacity: 80); opacity: 0.8; position: absolute; top: 0; left: 0;}
#img1 {width: 400px; height: 400px;}
span {position: absolute; width: 400px; height: 30px; line-height: 30px; text-align: center;
top: -50px; left: 0; font-family: '微软雅黑';}
</style>
<script>
window.onload = function() {
var oPrev = document.getElementById('prev');
var oNext = document.getElementById('next');
var oP = document.getElementById('p1');
var oStrong = document.getElementById('strong1');
var oImg = document.getElementById('img1');
var aBtn = document.getElementsByTagName('input');
var arrUrl = ['img/2_1.jpg', 'img/2_2.jpg', 'img/2_3.jpg', 'img/2_4.jpg'];
var arrText = ['文字一', '文字二', '文字三', '识文断字'];
var num = 0;
var onOff = true;
aBtn[0].onclick = function() {
onOff = true;
document.getElementsByTagName('span')[0].innerHTML = '图片可从最后一张跳转到第一张循环切换';
};
aBtn[1].onclick = function() {
onOff = false;
document.getElementsByTagName('span')[0].innerHTML = '图片只能到最后一张\或只能到第一张切换';
};
// 初始化
function fnTab() {
oP.innerHTML = arrText[num];
oStrong.innerHTML = num + 1 + ' / ' + arrText.length;
oImg.src = arrUrl[num];
}
fnTab();
oPrev.onclick = function() {
num--;
if(num == -1) {
if(onOff) {
num = arrText.length - 1;
} else {
alert('这已经是第一张了，不能再往前了~~');
num = 0;
}
//num = arrText.length-1;
}
fnTab();
};
oNext.onclick = function() {
num++;
if(num == arrText.length) {
if(onOff) {
num = 0;
} else {
alert('已经到最后一张啦~');
num = arrText.length - 1;
}
}
fnTab();
};
};
</script>
</head>
<body>
<input type="button" value="循环切换" />
<input type="button" value="顺序切换" />
<div id="box">
<span>图片可从最后一张跳转到第一张循环切换</span>
<a id="prev" href="javascript:;"> < </a>
<a id="next" href="javascript:;">></a>
<p id="p1">图片文字加载中……</p>
<strong id="strong1">图片数量计算中……</strong>
<img id="img1" />
</div>
</body>
</html>
