private void Helper_DownloadComplete(object sender, EventArgs e)
 {
     dialogResult = DownloadDialogResult.Complete;
     OnDownloadAsyncComplete(FileDownloaded, true, "");
 }
 private void ContentDialog_SecondaryButtonClick(ContentDialog sender, ContentDialogButtonClickEventArgs args)
 {
     dialogResult = DownloadDialogResult.CancelByUser;
     helper.ForceCancelTask();
 }
 private void Helper_DownloadCancel(object sender, string e)
 {
     dialogResult = DownloadDialogResult.CancelBySystem;
     OnDownloadAsyncComplete(FileDownloaded,false, e);
 }