public MainViewModel() { m_serializationService = ServiceLocator.Current.GetInstance<ISerializationService>(); Messenger.Default.Register<string>(this, "FileSaved", (pathIGotFromTheUser) => { m_serializationService.SaveProject(pathIGotFromTheUser); //Give a feedback that everything has been correctly saved(for test purpose, a MessageBox.Show() ) Messenger.Default.Send<NotificationMessage>(new NotificationMessage("WentWell")); }); }