如何将MultipartFormDataContent（带附件）发布到REST API？

Question

我在asp.net mvc中有一个api：

public class UploadController : Controller
{
   ...
    public ActionResult Post(UploadModel uploadModel)

我希望从测试客户端调用此api，附加文件。

using (var httpClient = new HttpClient())
                {
               httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("multipart/form-data"));
                    var byteArrayContent = new ByteArrayContent(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 });
                    byteArrayContent.Headers.ContentType = MediaTypeHeaderValue.Parse("text/csv");
    var uploadModel = new UploadModel { Allergene = "Anders", Description = "Desc", Email = "and@juu.com" };

    var content = new StringContent(JsonConvert.SerializeObject(uploadModel), Encoding.UTF8, "application/json");

                    var multipartFormDataContent = new MultipartFormDataContent
                    {
                        {content},
                        {byteArrayContent, "\"file\"", "\"feedback.csv\""}
                    };
                    var result = httpClient.PostAsync("http://localhost:53411/Upload/Post", multipartFormDataContent).Result;
}

如果我发布multipartFormDataContent，我不会在我的模型上获得属性。如果我发布内容，我会获得属性，但显然不是附件。

我错过了什么？