title: get always null when using IFormFile and [frombody] object in asp.net core 2 and swagger
body: <p>i get null when i  add [frombody] attribute , before i add it its work correctly but i want to get my object from body, i use asp.net core and swagger </p>
  
  <p>its my controller:</p>
  
  <pre><code>[HttpPost]
  [Route("add-content")]
  public async Task AddConten(IFormFile uploadedFile,[FromBody]ContentDTO content)
  {
      var fileName = Guid.NewGuid() + "-" + uploadedFile.FileName;
      var path = (Directory.GetCurrentDirectory() + @"UplodedFiles\ContentFiles\"+fileName);
  
      using (var stream = new FileStream(path, FileMode.Create))
      {
          await uploadedFile.CopyToAsync(stream);
      }
  }
  </code></pre>
  
  <p>its My Filter:</p>
  
  <pre><code>public class FileUploadOperation :IOperationFilter
  {
      public void Apply(Operation operation, OperationFilterContext context)
      {         
          if (operation.OperationId  == "ApiCpAdd-users-by-filePost" ||
              operation.OperationId == "ApiPortalAdd-contentPost")
          {
              operation.Parameters.RemoveAt(0);
              operation.Parameters.Add(new NonBodyParameter
              {
                  Name = "uploadedFile",
                  In = "formData",
                  Description = "Upload File",
                  Required = true,
                  Type = "file"
              });
              operation.Consumes.Add("multipart/form-data");
          }
      }
  }
  </code></pre>