async void ExecuteExportBackupCommand() { try { var picker = new FileSavePicker(); picker.DefaultFileExtension = ".json"; picker.SuggestedFileName = $"hohoema-backup-{DateTime.Today:yyyy-MM-dd}"; picker.FileTypeChoices.Add("Hohoema backup File", new List <string>() { ".json" }); var file = await picker.PickSaveFileAsync(); if (file != null) { await _backupManager.BackupAsync(file, default); _notificationService.ShowLiteInAppNotification_Success("バックアップを保存しました"); } } catch (Exception e) { _logger.ZLogError(e, "Backup export failed"); } }