我将 .net5 mvc 项目中的文件列表发送到 .net5 api，但只得到一个文件而不是文件列表

Question

I have two models as follows:

public class Category
{
  public int Id { get; set; }
  public string Name { get; set; }
  public List<CategoryDetail> CategoryDetails { get; set; }
}


public class CategoryDetail
{
  public int Id { get; set; }
  public string Url { get; set; }
  public IFormFile File { get; set; }
  public Category Category { get; set; }
}

I can bind categorydetail model in .NET5 mvc with list of files. The problem is, I get only one file when it post to the .NET5 API. It seems to me that MultipartFormDataContent cannot bind multiple files when loop through each file.

The following code send post request to the API

var multiForm = new MultipartFormDataContent();
multiForm.Add(new StringContent(entity.Id), "Id");
multiForm.Add(new StringContent(Convert.ToString(entity.Name)), "Name");

**foreach (var item in entity.CategoryDetails)
{
  int i = 0;
  multiForm.Add(new StringContent(item.Url), 
 "CategoryDetails[" + i + "].Url");
  multiForm.Add(new StreamContent(item.File.OpenReadStream()), 
 "CategoryDetails[" + i + "].File", item.File.FileName);
  i++;
}**

 var request = new HttpRequestMessage(HttpMethod.Post, url) { Content = multiForm };

 var accessToken = _context.HttpContext.User.Claims.FirstOrDefault(c => 
 c.Type==AppClaims.AccessToken)?.Value;
 if (!string.IsNullOrEmpty(accessToken))
 {
   request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
 }

 var client = _clientFactory.CreateClient("ApiServer");
 var response = await client.SendAsync(request).ConfigureAwait(false);

Api Controller Function as follows:

    [RequestSizeLimit(2147483648)]
    [HttpPost("add")]
    [Consumes(@"application/octet-stream", @"application/x-www-form-urlencoded", "multipart/form-data")]
    [ProducesResponseType(200, Type = typeof(BaseResponse))]

    public async Task<IActionResult> AddCategorySection([FromForm] 
    Category model)
    {
    }

Answer 1

The above code will work correctly. I just wrongly initialize the increment variable inside the foreach loop and each time initialize to 0. The correct code is as follows-

int i = 0;
foreach (var item in entity.CategoryDetails)
{
  multiForm.Add(new StringContent(item.Url), 
  "CategoryDetails[" + i + "].Url");
  multiForm.Add(new StreamContent(item.File.OpenReadStream()), 
  "CategoryDetails[" + i + "].File", item.File.FileName);
  i++;
}