完美JQuery图片切换效果的简单实现

body { font-family:"Microsoft Yahei"; }
body,ul,li,img,h3,dl,dd,dt,h1{margin:0px;padding:0px;list-style:none;}  
img{vertical-align: top;}
/***大图切换***/
.scroll_view{margin: 0px auto;overflow:hidden;position: relative;}
.photo_view li{position:absolute;width: 100%;}
.photo_view li em,.photo_view li h3{position: absolute;bottom: 0px;z-index: 1;height: 35px;line-height: 35px;width: 100%;left: 0px;}
.photo_view li em{z-index: 1;background:rgba(0,0,0,0.5);filter: progid:DXImageTransform.Microsoft.gradient( GradientType = 0,startColorstr = '#50000000',endColorstr = '#50000000');_background:#000;}
.photo_view li h3{z-index: 2;text-indent: 1em;font-weight: normal;}
.photo_view li h3 a{color:#fff;}
.photo_view li h3 a:hover{color:#f60;}
.small_photo{position: absolute;bottom: 40px;right: 10px;cursor: pointer;z-index: 4;}
.small_photo li {float: left;padding-right: 10px;}
.small_photo li img{width: 80px;height: 35px;border: solid 2px #ccc;border-radius: 2px;}
.small_photo li.active img{border: solid 2px #f60;}

<!-- start:大图切换 -->
<div class="scroll_view">
  <ul class="photo_view">
    <li><img src="images/ad1.jpg" alt="" class="" /><em></em><h3><a href="javascript:void(0);">图片效果1</a></h3></li>
    <li><img src="images/ad2.jpg" alt="" class="" /><em></em><h3><a href="javascript:void(0);">图片效果2</a></h3></li>
    <li><img src="images/ad3.jpg" alt="" class="" /><em></em><h3><a href="javascript:void(0);">图片效果3</a></h3></li>
    <li><img src="images/ad4.jpg" alt="" class="" /><em></em><h3><a href="javascript:void(0);">图片效果4</a></h3></li>
  </ul>
  <ul class="small_photo"></ul>
</div>
<!-- End:大图切换 -->

$.fn.extend({  
  imgScroll:function(options){    
    var def={phtot_parent:$(".scroll_view"),photo_view:$(".photo_view"),small_photo:$(".small_photo"),speed:800,isauto:true,width:800,height:349},
      opt=$.extend({},def,options),
      $photo_view=opt.photo_view,
      $small_photo=opt.small_photo,
      speed=opt.speed,
      isauto=opt.isauto,
      index=0,
      _length=$photo_view.find("li").length,
      strTime=null;
    opt.phtot_parent.css({width:opt.width,height:opt.height});
    $photo_view.find("li:not(:first)").hide()//.find("img").hide();
    $photo_view.find("li").each(function(i){
      $small_photo.append('<li><img src="'+$(this).find("img").attr("src")+'" alt="" class="" /></li>');
    })
    $small_photo.find("li:first").addClass("active");
    //小图鼠标动作
    $small_photo.find("li").bind("mouseenter",function(){  
      clearInterval(strTime);
      if(index!=$(this).index()){
        index=$(this).index();  
        animate(index)
      }
    }).bind("mouseleave",function(){      
      if(isauto){
        start();  
      }
    });
    //大图悬停动作
    $photo_view.find("li").bind("mouseenter",function(){  
      clearInterval(strTime);      
    }).bind("mouseleave",function(){      
      if(isauto){
        start();  
      }
    });
    //自动播放
    if(isauto){
      start();  
    }
    //启动自动播放
    function start(){
      strTime=setInterval(function(){
        index >= _length-1 ? index=0 : index++;
        animate(index);
      },speed);
    }
    //动画效果
    function animate(_index){//console.log(_index)
      $small_photo.find("li").eq(_index).addClass('active').siblings().removeClass("active");//改变小图导航样式
      $photo_view.find("li").eq(_index).css("z-index",1).siblings().css("z-index",0);//控制absolute的层级
      $photo_view.find("li").eq(_index).show().find("img").css({"opacity": 0});  //装大图的opacity设置为0  
      $photo_view.find("li").eq(_index).find("img").animate({opacity:1},300,function(){
        $(this).removeAttr("style");//动画之后删除opacity
        $photo_view.find("li").eq(_index).show().siblings().hide();//显示大图  
      });//展示当前显示动画
    }
  }
});

<script type="text/javascript">
  $(function(){$("scroll_view").imgScroll({photo_view:$(".photo_view"),small_photo:$(".small_photo"),speed:3000,isauto:true}); 
  })
</script>