jQuery点击头像上传并预览图片

<div class="img_show img_show1">  <img src="img2/img06.jpg" width="103" height="103" alt="">  <input type="file" class="upfile" accept="*/*"></div>

DS.upfile = function(){  $('.img_show').each(function(){   var $this = $(this),    btn = $this.find('.upfile'),    img = $this.find('img');   btn.on('change',function(){    var file = $(this)[0].files[0],     imgSrc = $(this)[0].value,     url = URL.createObjectURL(file);    if (!//.(jpg|jpeg|png|JPG|PNG|JPEG)$/.test(imgSrc)){     alert("请上传jpg或png格式的图片！");     return false;    }else{     img.attr('src',url);     img.css({'opacity':'1'});    }   });  }); }();