幻灯片（jquery实现）

html代码：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>幻灯片特效 在线演示 DIVCSS5</title>
<style type="text/css">
body {font-size:12px; color:#222; text-align:center; font-family:Verdana,Arial,Helvetica,sans-serif; background:#f0f0f0;}
ul,li {list-style:none; margin:0px; padding:0px;}
img {border:0;}
/* 以下特效CSS */
.focus {width:600px; height:280px; margin:0 auto; overflow:hidden; position:relative;}
.focus ul {height:280px; position:absolute;}
.focus ul li {float:left; width:600px; height:280px; overflow:hidden; position:relative; background:#000;}
.focus ul li div {position:absolute; overflow:hidden;}
.focus .btnBg {position:absolute; width:600px; height:20px; left:0; bottom:0; background:#000; display:none;}
.focus .btn {position:absolute; width:580px; height:23px; padding:0px 10px 0px 10px; right:0; bottom:6px; text-align:right;}
.focus .btn span {display:inline-block; _display:inline; _zoom:1; width:25px; height:24px; line-height:24px; text-align:center; _font-size:0; margin-left:5px; cursor:pointer; background:#fff;}
.focus .btn span.on {background:#fff;}
.focus .preNext {width:45px; height:100px; position:absolute; top:90px; background:url(/Images/sprite.png) no-repeat 0 0; cursor:pointer;}
.focus .pre {left:0;}
.focus .next {right:0; background-position:right top;}
</style>
<script type="text/javascript" src="/Javascript/jquery.js"></script>
<script type="text/javascript" src="/Javascript/9.js"></script>
<script type="text/javascript">
	$(document).ready(function(){
	  	$.focus("#focus001");
	});
</script>
</head>

<body>
<div class="focus" id="focus001">
    <ul>
        <li><a href="http://www.divcss5.com/" target="_blank"><img src="/Images/01.jpg" alt="jquery特效" /></a></li>
        <li><a href="http://www.divcss5.com/" target="_blank"><img src="/Images/02.jpg" alt="DIVCSS5" /></a></li>
        <li><a href="http://www.divcss5.com/css-texiao/texiao735.shtml" target="_blank"><img src="/Images/03.jpg" alt="点击左右滚动jquery焦点图特效" /></a></li>
    </ul>
</div>
</body>
</html>

javascript代码：

$(function() {
	jQuery.focus = function(slid) {
		var sWidth = $(slid).width(); //获取焦点图的宽度（显示面积）
		var len = $(slid).find("ul li").length; //获取焦点图个数
		var index = 0;
		var picTimer;

		//以下代码添加数字按钮和按钮后的半透明条，还有上一页、下一页两个按钮
		var btn = "<div class='btnBg'></div><div class='btn'>";
		for(var i=0; i < len; i++) {
			var ii = i+1;
			btn += "<span>"+ii+"</span>";
		}
		btn += "</div><div class='preNext pre'></div><div class='preNext next'></div>";
		$(slid).append(btn);
		$(slid).find("div.btnBg").css("opacity",0.5);

		//为小按钮添加鼠标滑入事件，以显示相应的内容
		$(slid+" div.btn span").css("opacity",0.4).mouseenter(function() {
			index = $(slid+" .btn span").index(this);
			showPics(index);
		}).eq(0).trigger("mouseenter");

		//上一页、下一页按钮透明度处理
		$(slid+" .preNext").css("opacity",0.2).hover(function() {
			$(this).stop(true,false).animate({"opacity":"0.5"},300);
		},function() {
			$(this).stop(true,false).animate({"opacity":"0.2"},300);
		});

		//上一页按钮
		$(slid+" .pre").click(function() {
			index -= 1;
			if(index == -1) {index = len - 1;}
			showPics(index);
		});

		//下一页按钮
		$(slid+" .next").click(function() {
			index += 1;
			if(index == len) {index = 0;}
			showPics(index);
		});

		//本例为左右滚动，即所有li元素都是在同一排向左浮动，所以这里需要计算出外围ul元素的宽度
		$(slid+" ul").css("width",sWidth * (len));

		//鼠标滑上焦点图时停止自动播放，滑出时开始自动播放
		$(slid).hover(function() {
			clearInterval(picTimer);
		},function() {
			picTimer = setInterval(function() {
				showPics(index);
				index++;
				if(index == len) {index = 0;}
			},2000); //此4000代表自动播放的间隔，单位：毫秒
		}).trigger("mouseleave");

		//显示图片函数，根据接收的index值显示相应的内容
		function showPics(index) { //普通切换
			var nowLeft = -index*sWidth; //根据index值计算ul元素的left值
			$(slid+" ul").stop(true,false).animate({"left":nowLeft},300); //通过animate()调整ul元素滚动到计算出的position
			$(slid+" .btn span").removeClass("on").eq(index).addClass("on"); //为当前的按钮切换到选中的效果
			$(slid+" .btn span").stop(true,false).animate({"opacity":"0.4"},300).eq(index).stop(true,false).animate({"opacity":"1"},300); //为当前的按钮切换到选中的效果
		}

	};

});