async with progress

gistfile1.cs

  var cl = new FileInfo(photo.ImageLocation).Length;
            request.Files.Add(new FileParameter
                                  {
                                      ContentLength = cl,
                                      Name = "photo[photo]",
                                      FileName = Path.GetFileName(photo.ImageLocation),
                                      Writer = s =>
                                                   {
                                                       using (var file = File.OpenRead(photo.ImageLocation))
                                                       {
                                                           byte[] buffer = new byte[16384]; //16k buffer
                                                           int bytesRead = 0;
                                                           int read = 0;
                                                           while ((read = file.Read(buffer, 0, buffer.Length)) > 0)
                                                           {

                                                               s.Write(buffer, 0, read);
                                                               s.Flush();
                                                               bytesRead += read;
                                                               System.Diagnostics.Debug.WriteLine("uploading: " + (int)((double)bytesRead / file.Length * 100) + "%");
                                                               _messengerHub.Publish(new PhotoUploadProgressed { Sender = null, Photo = photo, Uploaded = bytesRead });
                                                           }
                                                           file.Close();
                                                       }
                                                   }

                                  });
            client.ExecuteAsync(request, (response) =>
                                             {
                                                 _messengerHub.PublishAsync(new PhotoUploadFinishedMessage
                                                                                {
                                                                                    Sender = null,
                                                                                    Photo = photo,
                                                                                    Response = response.Content,
                                                                                    Cancelled = false,
                                                                                    Error = response.ErrorException
                                                                                });
                                                 Console.WriteLine("finished");
                                             });