<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
<html>  
 <head>  
  <title>js大图显示--www.jb200.com</title>  
  <meta name="Generator" content="EditPlus">  
  <meta name="Author" content="">  
  <meta name="Keywords" content="">  
  <meta name="Description" content="">  
 </head>  
<div id="outerdiv" style="position:fixed;top:0;left:0;background:rgba(0,0,0,0.7);z-index:2;width:100%;height:100%;display:none;">  
<div id="innerdiv" style="position:absolute;"><img id="bigimg" style="border:5px solid #fff;" src="" /></div>  
</div>  
 <body>  
 <script type="text/
javascript" src="C:/Users/shibin/Desktop/js/
jquery-2.0.2.min.js"></script>  
  <script>  
    $(function(){  
        $(".pimg").click(function(){  
            var _this = $(this);//将当前的pimg元素作为_this传入函数  
            imgShow("#outerdiv", "#innerdiv", "#bigimg", _this);  
        });  
    });  
  function imgShow(outerdiv, innerdiv, bigimg, _this){  
    var src = _this.attr("src");//获取当前点击的pimg元素中的src属性  
    $(bigimg).attr("src", src);//设置#bigimg元素的src属性  
  
        /*获取当前点击图片的真实大小,并显示弹出层及大图*/  
    $("<img/>").attr("src", src).load(function(){  
        var windowW = $(window).width();//获取当前窗口宽度  
        var windowH = $(window).height();//获取当前窗口高度  
        var realWidth = this.width;//获取图片真实宽度  
        var realHeight = this.height;//获取图片真实高度  
        var imgWidth, imgHeight;  
        var scale = 0.8;//缩放尺寸,当图片真实宽度和高度大于窗口宽度和高度时进行缩放  
          
        if(realHeight>windowH*scale) {//判断图片高度  
            imgHeight = windowH*scale;//如大于窗口高度,图片高度进行缩放  
            imgWidth = imgHeight/realHeight*realWidth;//等比例缩放宽度  
            if(imgWidth>windowW*scale) {//如宽度扔大于窗口宽度  
                imgWidth = windowW*scale;//再对宽度进行缩放  
            }  
        } else if(realWidth>windowW*scale) {//如图片高度合适,判断图片宽度  
            imgWidth = windowW*scale;//如大于窗口宽度,图片宽度进行缩放  
                        imgHeight = imgWidth/realWidth*realHeight;//等比例缩放高度  
        } else {//如果图片真实高度和宽度都符合要求,高宽不变  
            imgWidth = realWidth;  
            imgHeight = realHeight;  
        }  
                $(bigimg).css("width",imgWidth);//以最终的宽度对图片缩放  
        var w = (windowW-imgWidth)/2;//计算图片与窗口左边距  
        var h = (windowH-imgHeight)/2;//计算图片与窗口上边距  
        $(innerdiv).css({"top":h, "left":w});//设置#innerdiv的top和left属性  
        $(outerdiv).fadeIn("fast");//淡入显示#outerdiv及.pimg  
    });  
      
    $(outerdiv).click(function(){//再次点击淡出消失弹出层  
        $(this).fadeOut("fast");  
    });  
}  
  </script>  
  <ul id="imglist">  
  <li><img class="pimg" src="/tupian/shangpintu.jpg" width="500px" /></li>  
  </ul>  
 </body>  
</html>