web api中MIME多部分流的意外结束

Question

MIME多部分流的意外结束。当覆盖Stream::GetStream MultipartFormDataStreamProvider方法时，MIME多部分消息未完成错误。我在GetStream方法中获取流并对其进行加密并返回它而不是它给我这个错误（MIME多部分流的意外结束）。我已经完成了所有以前的解决方案，但是没有用。 这是我的代码：

var Savedfiledata = await Request.Content.ReadAsMultipartAsync(provider).ContinueWith(

                (Task<CustomMultipartFormData> readTask) =>
                {
                    CustomMultipartFormData CMF = readTask.Result;// Here Error is comming

                    // Create response containing information about the stored files.

                    return CMF.FileData.Select(fileData =>
                    {
                        FileInfo info = new FileInfo(fileData.LocalFileName);
                        ContentDispositionHeaderValue disposition = fileData.Headers.ContentDisposition;

                        string filename = (disposition != null && disposition.FileName != null) ? disposition.FileName : string.Empty;

                        CS_FileUpload FileObj = new CS_FileUpload()
                        {
                            FileName = filename.Replace("\"", ""),
                            FileUniqueName = info.Name,
                            FileSize = (info.Length / 1024),
                            FilePath = info.DirectoryName,
                            FileType = info.Extension,
                            InsertDate = info.LastWriteTimeUtc,
                        };

                        DAObj.CS_FileUpload.Add(FileObj);
                        return FileObj;

                    }).ToList();

                });

公共覆盖Stream GetStream（HttpContent filedata，HttpContentHeaders标头）         {

        Stream reqStream = filedata.ReadAsStreamAsync().Result;

        using (MemoryStream stream = new MemoryStream())
        {
            reqStream.CopyTo(stream);
            MemoryStream getEncBytes = Encrypt(stream, GenerateKey());
            return getEncBytes;
        }

    }