public UploadObjectViewModel(UploadObject uploadObject)
    {
      this.uploadObject = uploadObject;

      Filename = uploadObject.Name;
      Id = uploadObject.ID;
      ContentType = uploadObject.ContentType;

      DownloadCommand = new RelayCommand(Download);
    }
 public UploadMessageViewModel(Message message)
   : base(message)
 {
   uploadObject = message.Room.GetUploadObject(message.ID);
 }