Ajax asp.net mvc 5 中的上传助手没有工作并获得空值

Question

我想使用 Upload control 在 asp.net mvc 5 中使用 Razor engine 保存图像。这些是我下面的代码，我认为一切都很好，但我不知道为什么 controller 中的 UploadImage 得到 null 并且没有得到选定的图像。有人可以帮我吗？

管理员控制器

根据一篇文章，我在控制器参数中使用了相同的名称 @html.upload("UploadImage")。

[HttpPost]
    public ActionResult AddSubGood(SubGood subgood, HttpPostedFileBase UploadImage)
    {
        var MainGoodId = subgood.FKMainGoodID;
        SubGoodRepositories blSubGood = new SubGoodRepositories();
        if (ModelState.IsValid)
        {
            subgood.FKMainGoodID = MainGoodId;
            if (blSubGood.Add(subgood))
            {
                return MessageBox.Show("added successfully", MessageType.Success);
            }
            else
            {
                return MessageBox.Show(" didn't add", MessageType.Error);
            }
        }
        else
        {
            return MessageBox.Show(ModelState.GetErrors(), MessageType.Warning);
        }

    }

AddSubGood.cshtml

根据一篇文章，我将enctype="multipart/form-data"添加到form

@using (Ajax.BeginForm("Admin", "AddSubGood", new AjaxOptions { HttpMethod = "Post", Url = "/Admin/AddSubGood" }, new{enctype="multipart/form-data" }))
{
 @Html.AntiForgeryToken()
 <div class="form-group">
             <div class="form-group">
               <div class="col-md-10">
                   @Html.Upload("UploadImage")
                   @Html.ValidationMessageFor(model => model.SubGoodURL)
               </div>
            @Html.LabelFor(model => model.SubGoodURL, new { @class = "control-label col-md-2" })
   </div>
}

UploadHelper.cs

 public static class UploadHelper
  {
  public static MvcHtmlString Upload(this HtmlHelper helper, string name, object htmlAttributes = null)
  {
    TagBuilder input = new TagBuilder("input");
    input.Attributes.Add("type", "file");
    input.Attributes.Add("id", helper.ViewData.TemplateInfo.GetFullHtmlFieldId(name));
    input.Attributes.Add("name", helper.ViewData.TemplateInfo.GetFullHtmlFieldName(name));

    if (htmlAttributes != null)
    {
        var attributes = HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes);
        input.MergeAttributes(attributes);
    }

    return new MvcHtmlString(input.ToString());
}

public static MvcHtmlString UploadFor<TModel, TValue>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TValue>> expression, object htmlAttributes = null)
{
    //helper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(expression))
    var data = ModelMetadata.FromLambdaExpression(expression, helper.ViewData);
    TagBuilder input = new TagBuilder("input");
    input.Attributes.Add("type", "file");
    input.Attributes.Add("id", helper.ViewData.TemplateInfo.GetFullHtmlFieldId(ExpressionHelper.GetExpressionText(expression)));
    input.Attributes.Add("name", helper.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(expression)));

    if (htmlAttributes != null)
    {
        var attributes = HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes);
        input.MergeAttributes(attributes);
    }

    return new MvcHtmlString(input.ToString());
   }
}

Answer 1

不支持使用Ajax.BeginForm上传文件。如果您改用 Html.BeginForm 它将起作用。如果你要 ajax post 你可以使用一些文件上传插件，比如 dropzonejs or Blueimp File Upload.

Ajax asp.net mvc 5 中的上传助手没有工作并获得空值

Ajax Upload helper in asp.net mvc 5 didn't work and gets Null value

asp.net-mvc

upload

ajax.beginform

razor

asp.net-mvc-5