多图上传预览

<ul class="upload_box"></ul>  // 预览图片容器
<div class="weui-uploader__input-box upload_input">
    <input class="weui-uploader__input upload_file" name="avatar[]" type="file" accept="image/*" onchange="setImagePreview(this)">
</div>

预览方法

var upload_btn = '<div class="weui-uploader__input-box upload_input">'+$('.upload_input').html()+'</div>';
    //下面用于图片上传预览功能
    function setImagePreview(avalue) {
        var docObj = avalue;

        var imgObjPreview = $('.upload_box');

        if(docObj.files && docObj.files[0])
        {
          //火狐下，直接设img属性
          // imgObjPreview.style.display = 'block';
          // imgObjPreview.style.maxWidth = '100%';
          // imgObjPreview.style.maxHeight = '85px';
          //imgObjPreview.src = docObj.files[0].getAsDataURL();

          //火狐7以上版本不能用上面的getAsDataURL()方式获取，需要一下方式
          // imgObjPreview.src = window.URL.createObjectURL(docObj.files[0]);
          imgObjPreview.append('<li><div class="upload_img"><img src="'+window.URL.createObjectURL(docObj.files[0])+'" width="100%" height="100%" /></div><i class="weui-icon-cancel remove_img" ></i></li>');
        }
        else
        {
          //IE下，使用滤镜
          docObj.select();
          var imgSrc = document.selection.createRange().text;
          var localImagId = docObj.nextElementSibling;
          //必须设置初始大小
          localImagId.style.width = "100%";
          // localImagId.style.height = "85px";
          //图片异常的捕捉，防止用户修改后缀来伪造图片
          try{
            localImagId.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)";
            localImagId.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc;
          }
          catch(e)
          {
            alert("您上传的图片格式不正确，请重新选择!");
            return false;
          }
          imgObjPreview.style.display = 'none';
          document.selection.empty();
        }

        $(docObj).parent().hide();

        if($('.upload_box li').length >= 3){
            return false;
        }

        $(docObj).parent().before(upload_btn);

        return true;
    }
    // 删除图片
    $("body").on("click",'.remove_img',function(){
        var index = $(this).index();
        $('.upload_input').eq((index - 1)).remove();
        $(this).parent().remove();

        i = 0;
        $('.upload_input').each(function(){
            if($(this).css('display') != 'none'){
                i++;
            }
        })
        if(i == 0){
            $('.upload_input').parent().append(upload_btn);
        }
    });