private void ExecuteAddEmployeeToVehicleCommand(Object obj) { if (vehiclesViewModel.SelectedVehicle != null) { var relation = new AddRelationController().AddRelation(socket, vehiclesViewModel.SelectedVehicle); var result = socket.AddVehicleToEmployeeRelation(relation); if (result == false) { System.Windows.MessageBox.Show("Fehler beim Hinzufügen der Relation"); } } parent.restartVehicleCommand(); }