【技巧】仿某宝网详情页宝贝放大镜效果

先来看效果吧：

HTML代码如下：

<!DOCTYPE html>
<html lang="zh-cn">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>放大镜效果练习</title>
    <link rel="stylesheet" type="text/css" href="css/index.css">
  <body>

    <div class="con-FangDa" id="fangdajing">
      <div class="con-fangDaIMg">
        <img src="/uploads/rs/304/hownr3so/bb.jpg"><!-- 正常现实的图片 -->
        <div class="magnifyingBegin"></div><!-- 滑块 -->
        <div class="magnifyingShow"><!-- 放大镜显示的图片 -->
          <img src="/uploads/rs/304/hownr3so/bb.jpg">
        </div>
      </div>

      <ul class="con-FangDa-ImgList"><!-- 图片显示列表 -->
        <li class="active"><img src="/uploads/rs/304/hownr3so/bb.jpg"></li>
        <li><img src="/uploads/rs/304/hownr3so/a.jpg"></li>
        <li><img src="/uploads/rs/304/hownr3so/bb.jpg"></li>
        <li><img src="/uploads/rs/304/hownr3so/a.jpg"></li>
        <li><img src="/uploads/rs/304/hownr3so/bb.jpg"></li>
      </ul>
    </div>  

        <script id="jquery_182" type="text/javascript" class="library" src="/js/sandbox/jquery/jquery-1.8.2.min.js"></script>
    <script id="jqueryplugins7_jquery_colorbox_132" type="text/javascript" class="library" src="/js/sandbox/jquery-plugins/jquery.colorbox-min.js"></script>

  </body>
</html>

CSS代码如下：

*{
    margin: 0;
    padding: 0;
}

/*主容器*/
.con-FangDa{
    width: 300px;
    height: 550px;

    background-color: cyan;
}
/*正常容器*/
.con-fangDaIMg{
    width: 300px;
    height: 450px;
    position: relative;
    background-color: #454545;
}
.con-fangDaIMg > img{
    width: 100%;
    height:100%;
    display: block;
}
/*滑块*/
.magnifyingBegin{
    width: 100px;
    height: 100px;
    left: 0;
    top: 0;
    background-color: #454545;
    opacity: 0.5;
    position: absolute;
    cursor: move;
    display: none;
}
/*放大镜显示区域*/
.magnifyingShow{
    width: 300px;
    height: 300px;
    display: none;
    position: absolute;
    right: -300px;
    top: 0;
    overflow: hidden;
    background-color: #454545;
}
.magnifyingShow > img{
    width: 900px;
    height: 1350px;
    margin-left:0;
    margin-top: 0;
}
/*设置选择图片容器*/
.con-FangDa-ImgList{
    list-style: none;
}
.con-FangDa-ImgList > li{
    width: 50px;
    height: 50px;
    float: left;
    margin: 4px 0 0 4px;
    cursor: pointer;
    border: 2px solid #454545;
    background-color: #454545;
}
.con-FangDa-ImgList > li:first-child{
    margin-left: 0;
}
.con-FangDa-ImgList > li > img{
    width: 100%;
    height: 100%;
}
.con-FangDa-ImgList > .active{
    border-color: red;
}

JS代码如下：

$(function(){

    $.fn.magnifying = function(){
        var that = $(this),
         $imgCon = that.find('.con-fangDaIMg'),//正常图片容器
            $Img = $imgCon.find('img'),//正常图片，还有放大图片集合
           $Drag = that.find('.magnifyingBegin'),//拖动滑动容器
           $show = that.find('.magnifyingShow'),//放大镜显示区域
        $showIMg = $show.find('img'),//放大镜图片
        $ImgList = that.find('.con-FangDa-ImgList > li >img'),
        multiple = $show.width()/$Drag.width();//倍数

        $imgCon.mousemove(function(e){
            $Drag.css('display','block');
            $show.css('display','block');
            //获取坐标的两种方法
            // var iX = e.clientX - this.offsetLeft - $Drag.width()/2,
            //  iY = e.clientY - this.offsetTop - $Drag.height()/2,    
            var iX = e.pageX - $(this).offset().left - $Drag.width()/2,
                iY = e.pageY - $(this).offset().top - $Drag.height()/2,    
                MaxX = $imgCon.width()-$Drag.width(),
                MaxY = $imgCon.height()-$Drag.height();
            /*这一部分可代替下面部分，判断最大最小值
            var DX = iX < MaxX ? iX > 0 ? iX : 0 : MaxX,
                DY = iY < MaxY ? iY > 0 ? iY : 0 : MaxY;
            $Drag.css({left:DX+'px',top:DY+'px'});         
            $showIMg.css({marginLeft:-3*DX+'px',marginTop:-3*DY+'px'});*/

            iX = iX > 0 ? iX : 0;
            iX = iX < MaxX ? iX : MaxX;
            iY = iY > 0 ? iY : 0;
            iY = iY < MaxY ? iY : MaxY; 
            $Drag.css({left:iX+'px',top:iY+'px'});         
            $showIMg.css({marginLeft:-multiple*iX+'px',marginTop:-multiple*iY+'px'});
            //return false;
        });
        $imgCon.mouseout(function(){
            $Drag.css('display','none');
            $show.css('display','none');
            //return false;
        });

        $ImgList.click(function(){
            var NowSrc = $(this).attr('src');
            $Img.attr('src',NowSrc);
            $(this).parent().addClass('active').siblings().removeClass('active');
        }); 
    }

    $("#fangdajing").magnifying();


});