private void RemoveTimetable(object parameter) { if (!ValidateParamsAsObject(parameter)) { ShowInfoWindow("Nie wybrano terminarza"); return; } var currentTimetable = (TimetableViewModel)parameter; if (timetableService.RemoveTimetable(currentTimetable.ID)) { UpdateTimetableGrid(); } else { ShowInfoWindow("Nie można usunąć terminarz"); return; } }