我上传图片文件时没有收到代码错误，却收到我自己设置的所需错误，我哪里做错了？

Question

当我想保存图像时，我遇到了问题，我在模型中强制出现了错误，但是在应用程序运行时我没有收到任何错误行，当我使用断点时，我看到图像出现了直到模型有效，但有效返回错误，但我找不到解决方案，你能帮忙吗？

我在“创建”页面上获取图像数据的字段

<div class="form-group my-3">
    <label asp-for="UniversityImage"></label>
    <input name="file" type="file" class="form-control" />
</div>

我的管理仪表板

 [HttpPost]
 [ValidateAntiForgeryToken]
 public async Task<IActionResult> Create([FromForm] UniversityDtoForInsertion universityDto, IFormFile file)
 {
     if (ModelState.IsValid)
     {
         string path = Path.Combine(Directory.GetCurrentDirectory(), "wwwroot", "images", file.FileName);

         await using (var stream = new FileStream(path, FileMode.Create))
         {
             await file.CopyToAsync(stream);
         }
         universityDto.UniversityImage = String.Concat("/images/", file.FileName);
         _serviceManager.UniversityService.CreateUniversity(universityDto);
         TempData["success"] = $"{universityDto.UniversityName} has been created.";
         return RedirectToAction("Index");
     }
     return View();

 }

数据传输对象

public record UniversityDto
{
    public int UniversityId { get; init; }

    [Required(ErrorMessage = "UniversityName is Required")]
    public string UniversityName { get; init; }

    [Required(ErrorMessage = "UniversityDescription is Required")]
    public string UniversityDescription { get; init; }

    [Required(ErrorMessage = "UniversityAddress is Required")]
    public string UniversityAddress { get; init; }

    [Required(ErrorMessage = "UniversityWebAddress is Required")]
    public string UniversityWebAddress { get; init; }

    [Required(ErrorMessage = "UniversityPhone is Required")]
    public string UniversityPhone { get; init; }

    [Required(ErrorMessage = "UniversityImage is Required")]
    public string UniversityImage { get; set; }

}

IUniversity服务层

University CreateUniversity(UniversityDtoForInsertion universityDto);

大学管理者层

 public University CreateUniversity(UniversityDtoForInsertion universityDto)
 {
     if (universityDto is null)
     {
         throw new ArgumentNullException(nameof(universityDto));
     }

     University university = _mapper.Map<University>(universityDto);

     _manager.University.Create(university);
     _manager.Save();
     return university;
 }

IUniversityRepository层

 public interface IUniversityRepository : IRepositoryBase<University>
 {
     IQueryable<University> GetAllUniversities(bool trackChanges);
     University? GetOneUniversity(int id, bool trackChanges);

     void CreateOneUni(University university);
     void UpdateOneUni(University university);
     void DeleteOneUni(University university);
 }

大学存储库层

 public void CreateOneUni(University university) => Create(university);

当我继续使用断点时，显示问题的点如下图所示，您能帮忙吗？

Answer 1

自从您通过

添加 UniversityImage

universityDto.UniversityImage = String.Concat("/images/", 文件.文件名);

尝试在检查 ModelState.IsValid 之前添加它，例如：

 universityDto.UniversityImage = String.Concat("/images/", file.FileName);
 if (ModelState.IsValid)
     {...}