基于JQuery实现图片轮播效果(焦点图)

自己写了一个纯jq形式的横向轮播焦点图，可点击小圆点或者左右按钮进行切换，属于定宽类型。改成自适应宽度的也不难，将CSS里面的bannerCon宽度改为百分比，再在JS里面将ul和li的宽度跟随父级容器的宽度变化即可，需要用到$(window).resize。

兼容到IE6+以上浏览器，有轮播速度和切换间隔两个参数可以改。

效果图如下：

html代码如下：

<HTML>
<head>
 <meta charset="utf-8">
 <title>banner图</title>
 <link href="css/style.css" rel="StyleSheet"/>
 <script src="js/JQuery-1.9.1.min.js"></script>
 <script src="js/common.js"></script>
</head>
<body>
 <div class="wrap">
 <div class="banner">
  <div class="bannerCon">
  <ul class="imglist">
   <li><a href="#"><img src="images/banner01.jpg" alt=""/></a></li>
   <li><a href="#"><img src="images/banner02.jpg" alt=""/></a></li>
   <li><a href="#"><img src="images/banner03.jpg" alt=""/></a></li>
  </ul>
  <ul class="BTnList clearfix">
   <li class="cur"><span></span></li>
   <li><span></span></li>
   <li><span></span></li>
  </ul>
  <span class="PRe-nex prev"><</span> 
  <span class="pre-nex next">></span> 
  </div>
 </div>
 </div>
</body>
</html>

Css样式如下：

@charset "utf-8";
/* 简单reset */
body, p, ul, ol, li {
 margin: 0;
 padding: 0;
}
ul, ol {
 list-style: none;
}
img { border:none; }
a,button{ outline: none; }
.clearfix:after {
 visibility: hidden;
 display: block;
 font-size: 0;
 content: " ";
 clear: both;
 height: 0;
} 
/* 具体样式 */
.banner {
 position: relative;
 height: 400px;
 overflow: hidden;
}
.banner .bannerCon {
 position: absolute;
 top: 0;
 left: 50%;
 width: 800px;
 height: 400px;
 margin-left: -400px;
 overflow: hidden;
}
.bannerCon .imgList {
 position: absolute;
 top: 0;
 left: 0;
 width: 99999px;
 height: 400px;
}
.bannerCon .imgList li {
 float: left;
 width: 800px;
 height: 400px;
}
.bannerCon .imgList li a {
 position: relative;
 display: block;
 height: 100%;
}
.bannerCon .imgList li img {
 width: 800px;
 height: 400px;
}
.bannerCon .pre-nex {
 display: none;
 position: absolute;
 top: 50%;
 width: 40px;
 height: 60px;
 margin-top: -40px;
 font: bold 40px/60px Simsun;
 color: #ccc;
 text-align: center;
 border:none;
 background: rgba(0,0,0,.30);
 filter:progid:DXImagetransform.microsoft.Gradient(startColorStr=#4c000000, endColorStr=#4c000000);
 cursor: pointer;
 z-index: 3;
}
.bannerCon .pre-nex.show { display: inline-block; }
.bannerCon .prev { left: 13%; }
.bannerCon .next { right: 13%; }
.bannerCon .btnList {
 position: absolute;
 left: 0;
 bottom: 20px;
 width: 100%;
 height: 12px;
 text-align:center;
 z-index: 2;
 _overflow: hidden;
}
.bannerCon .btnList li { display: inline; }
.bannerCon .btnList li span {
 display: inline-block;
 width: 12px;
 height: 12px;
 margin: 0 5px;
 border-radius: 6px;
 background-color:#14829e;
 Cursor: pointer;
}
.bannerCon .btnList li.cur span { background-color: #f30; }

Js代码如下：

//加载在文本读取之后的js语句 开始 =============================================================
 function scroll(obj,speed,interval){ //父级容器，轮播速度，切换间隔
  $("."+obj).each(function(){
   var $box = $(this),
   $imgUl = $box.children(".imgList"),
   $imgLi = $imgUl.children("li"),
   $btnUl = $box.children(".btnList"),
   $btnLi = $btnUl.children("li"),
   $btnPreNex = $box.children(".pre-nex"),
   $btnPre = $box.children(".prev"),
   $btnNex = $box.children(".next"),
   n = $imgLi.length,
   width = $imgLi.width(),
   left = parseFloat($imgUl.css("left")),
   k = 0,
   Player;
   $imgUl.css("width",n*width);
   function scroll(){    //轮播事件
    $imgUl.stop().Animate({left:-width},speed,function(){
     k += 1;
     $imgUl.css("left",0);
     $imgUl.children("li:first").appendTo($(this));
     $btnLi.removeClass('cur');
     if(k >= n){
      k = 0;
     }
     $btnUl.children("li").eq(k).addClass('cur');   
    });
   }
   $btnLi.click(function(){   //小圆点点击事件
    var index = $btnLi.index(this); 
    $(this).addClass('cur').siblings("li").removeClass('cur');
    if(index >= k){
     var dif = index-k;
     left = -dif*width;
     $imgUl.stop().animate({left:left},speed,function(){
      $imgUl.css("left",0);
      $imgUl.children("li:lt("+dif+")").APPendTo($imgUl); 
     });
    }
    else{
     var j = n-(k-index);
     $imgUl.css("left",(index-k)*width);
     $imgUl.children("li:lt("+j+")").appendTo($imgUl);
     $imgUl.stop().animate({left:0},speed); 
    }
    k = index;
   }); 
   $btnPreNex.click(function(){  //左右按钮点击事件
    var index = $btnLi.index(this);  
    if($(this).hasClass('next')){
     if(!$imgUl.is(":animated")){
      k += 1;
      $imgUl.animate({left:-width},speed,function(){
       $imgUl.css("left",0);
       $imgUl.children("li:first").AppendTo($(this));
       if(k >= n){
        k = 0;
       }
       $btnUl.children("li").removeClass('cur').eq(k).addClass('cur');
      });
     }
    }
    else {
     if(!$imgUl.is(":animated")){
      k += -1;
      $imgUl.css("left",-width);
      $imgUl.children("li:last").prependTo($imgUl);
      $imgUl.stop().animate({left:0},speed);
      if(k < 0){
       k = n-1;
      }
      $btnUl.children("li").removeClass('cur').eq(k).addClass('cur');
     }
    }
   });  
   $box.hover(      //鼠标移入、移出事件
    function(){
     clearInterval(Player);
     $btnPreNex.addClass('show');
    },
    function(){
     Player = SetInterval(function(){scroll()},interval);
     $btnPreNex.removeClass('show');
    }
    );
   Player = setInterval(function(){scroll()},interval);
  });
 } 
 $(function () {       //读取轮播事件
  Scroll("bannerCon",600,4000);
 });