private async void DoDeleteRoom() { var dialog = new UserDialogBox("", $"Raum [{SelectedRoom.Name}] wirklich löschen?", MessageBoxButton.OKCancel); var result = await dialog.ShowMahAppsDialog(); if (result == MessageDialogResult.Affirmative) { var roomToDelete = SelectedRoomObject; var updatedPractice = SelectedMedicalPracticeObject.RemoveRoom(roomToDelete.Id); UpdateMedicalPractice(updatedPractice); Rooms.Remove(SelectedRoom); SelectedRoom = null; } }