轮播

<div class="slider">
<ul class="slider-main">
<li class="slider-panel">
<a href=""><img src="1.jpg"></a>
</li>
<li class="slider-panel">
<a href=""><img src="2.jpg"></a>
</li>
<li class="slider-panel">
<a href=""><img src="3.jpg"></a>
</li>
<li class="slider-panel">
<a href=""><img src="4.jpg"></a>
</li>
</ul>
<div class="slider-extra">
<ul class="slider-nav">
<li class="slider-item"><img src="1.jpg" alt=""/></li>
<li class="slider-item"><img src="2.jpg" alt=""/></li>
<li class="slider-item"><img src="3.jpg" alt=""/></li>
<li class="slider-item"><img src="4.jpg" alt=""/></li>
</ul>
<div class="slider-page">
<a class="slider-pre" href="javascript:;;"><</a>
<a class="slider-next" href="javascript:;;">></a>
</div>
</div>
</div>
<script>
$(document).ready(function() {
var length,
currentIndex = 0,
interval,
hasStarted = false, //是否已经开始轮播
t = 3000; //轮播时间间隔
length = $('.slider-panel').length;
//将除了第一张图片隐藏
$('.slider-panel:not(:first)').hide();
//将第一个slider-item设为激活状态
$('.slider-item:first').addClass('slider-item-selected');
//隐藏向前、向后翻按钮
$('.slider-page').hide();
//鼠标上悬时显示向前、向后翻按钮,停止滑动，鼠标离开时隐藏向前、向后翻按钮，开始滑动
$('.slider-panel, .slider-pre, .slider-next').hover(function() {
stop();
$('.slider-page').show();
}, function() {
$('.slider-page').hide();
start();
});
$('.slider-item').hover(function(e) {
stop();
var preIndex = $(".slider-item").filter(".slider-item-selected").index();
currentIndex = $(this).index();
play(preIndex, currentIndex);
}, function() {
start();
});
$('.slider-pre').unbind('click');
$('.slider-pre').bind('click', function() {
pre();
});
$('.slider-next').unbind('click');
$('.slider-next').bind('click', function() {
next();
});
/**
* 向前翻页
*/
function pre() {
var preIndex = currentIndex;
currentIndex = (--currentIndex + length) % length;
play(preIndex, currentIndex);
}
/**
* 向后翻页
*/
function next() {
var preIndex = currentIndex;
currentIndex = ++currentIndex % length;
play(preIndex, currentIndex);
}
/**
* 从preIndex页翻到currentIndex页
* preIndex 整数，翻页的起始页
* currentIndex 整数，翻到的那页
*/
function play(preIndex, currentIndex) {
$('.slider-panel').eq(preIndex).fadeOut(500)
.parent().children().eq(currentIndex).fadeIn(1000);
$('.slider-item').removeClass('slider-item-selected');
$('.slider-item').eq(currentIndex).addClass('slider-item-selected');
}
/**
* 开始轮播
*/
function start() {
if(!hasStarted) {
hasStarted = true;
interval = setInterval(next, t);
}
}
/**
* 停止轮播
*/
function stop() {
clearInterval(interval);
hasStarted = false;
}
//开始轮播
start();
});
</script>