DataAnnotations的FileExtensions属性在MVC中不起作用

问题描述

我尝试在MVC中使用HTML FileUpload控件上传文件。我想验证文件只接受特定的扩展名。我曾尝试使用DataAnnotations命名空间的FileExtensions属性，但它不工作。请参阅下面的代码 -

  public class FileUploadModel 
 {
 [必需，FileExtensions（Extensions = xlsx，.xls），ErrorMessage =请选择一个Excel文件。）] 
 public HttpPostedFileBase File {get;组; } 
 
 $ 
 
 $ p $在控制器中，我写的代码如下 -  
  [HttpPost] 
 public ActionResult Index（FileUploadModel fileUploadModel）
 {
 if（ModelState.IsValid） 
 fileUploadModel.File.SaveAs（Path.Combine（Server.MapPath（〜/ UploadedFiles），Path.GetFileName（fileUploadModel.File.FileName）））; 
 
 return View（）; 
 
 
 
 
 
在视图中，我写下了代码 -  $ / 
 
 
  @using（Html.BeginForm（Index，FileParse，FormMethod.Post，new {enctype =multipart / form-data}）） 
 {
 @ Html.Label（Upload Student Excel：）
< input type =filename =fileid =file/> 
< input type =submitvalue =Import/> 
 @ Html.ValidationMessageFor（m => m.File）
} 
  
当我运行应用程序并给出一个无效的文件扩展名，它不显示我的错误信息。 
我知道编写自定义验证属性的解决方案，但我不想使用自定义属性。请指出我出错的地方。
解决方案
我有同样的问题，我解决了创建一个新的ValidationAttribute。 > 
 
 
像这样：
 
 pre $ { AllowMultiple = false，Inherited = true）] 
 public class FileExtensionsAttribute：ValidationAttribute 
 {
 private List< string> AllowedExtensions {get;组; } 
 $ b public FileExtensionsAttribute（string fileExtensions）
 {
 AllowedExtensions = fileExtensions.Split（new char [] {'，'}，StringSplitOptions.RemoveEmptyEntries）.ToList（）; 
} 
 
 public override bool IsValid（object value）
 {
 HttpPostedFileBase file = value as HttpPostedFileBase; 
 
 if（file！= null）
 {
 var fileName = file.FileName; 
 
 return AllowedExtensions.Any（y => fileName.EndsWith（y））; 
} 
 
 return true; 
 
 
 
 
 
 
 $ b现在，只需使用这个：
  [b]文件扩展名（jpg，jpeg，png，gif，ErrorMessage =您的错误信息。]] 
 public HttpPostedFileBase Imagem {得到;组; } 
  
我帮了忙。 
拥抱！
 
I am trying to upload a file using HTML FileUpload control in MVC. I want to validate the file to accept only specific extensions. I have tried using FileExtensions attribute of DataAnnotations namespace, but its not working. See code below -
public class FileUploadModel
    {
        [Required, FileExtensions(Extensions = (".xlsx,.xls"), ErrorMessage = "Please select an Excel file.")]
        public HttpPostedFileBase File { get; set; }
    }
In the controller, I am writing the code as below -
[HttpPost]
        public ActionResult Index(FileUploadModel fileUploadModel)
        {
            if (ModelState.IsValid)
                fileUploadModel.File.SaveAs(Path.Combine(Server.MapPath("~/UploadedFiles"), Path.GetFileName(fileUploadModel.File.FileName)));

            return View();
        }
In View, I have written below code -
@using (Html.BeginForm("Index", "FileParse", FormMethod.Post, new { enctype = "multipart/form-data"} ))
{
    @Html.Label("Upload Student Excel:")
    <input type="file" name="file" id="file"/>
    <input type="submit" value="Import"/>
    @Html.ValidationMessageFor(m => m.File)
}
When i run the application and give an invalid file extension, its not showing me the error message.I am aware of solution to write custom validation attribute, but I dont want to use custom attribute. Please point out where I am going wrong.
 解决方案 
I had the same problem and I resolved creating a new ValidationAttribute.
Like this:
    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
    public class FileExtensionsAttribute : ValidationAttribute
    {
        private List<string> AllowedExtensions { get; set; }

        public FileExtensionsAttribute(string fileExtensions)
        {
            AllowedExtensions = fileExtensions.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries).ToList();
        }

        public override bool IsValid(object value)
        {
            HttpPostedFileBase file = value as HttpPostedFileBase;

            if (file != null)
            {
                var fileName = file.FileName;

                return AllowedExtensions.Any(y => fileName.EndsWith(y));
            }

            return true;
        }
    }
Now, just use this:
[FileExtensions("jpg,jpeg,png,gif", ErrorMessage = "Your error message.")]
public HttpPostedFileBase Imagem { get; set; }
I have helped.Hugs!
                        
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