根据类选择器获取li里面img的src值
<li><img id="photo" name="photo" src="/Upload/image/artimg/2017090159a8d1461f21a.png"style="width:9%;margin:3px;"></li>
<li><img id="photo" name="photo" src="/Upload/image/artimg/2017090159a8d1461f21a.png"style="width:9%;margin:3px;"></li>
<li><img id="photo" name="photo" src="/Upload/image/artimg/2017090159a8d1461f21a.png"style="width:9%;margin:3px;"></li>
<li class="classify-active"><img id="photo" name="photo" src="/Upload/image/artimg/20170118587f0767ed2ef.jpg" style="width:9%;margin:3px;"></li>
获取src值的js代码为：var src=$(".classify-active").find("img").attr('src');
