private void ReceiveChangePageMessage(ChangePageMessage action)
 {
     if (action.ChangeBy == ChangePageMessage.MessageType.Type)
     {
         ChangeViewModelByType(action.ViewModelType);
     }
     else
     {
         ChangeViewModelByInstance(action.ViewModelInstance);
     }
 }
 private void NavigateTo(Type viewModel)
 {
     var msg = new ChangePageMessage(viewModel);
     Messenger.Default.Send<ChangePageMessage>(msg);
 }
        private void PostLogIn()
        {
            var loggedInMessage = new NotificationMessage("LoggedIn");
            MessengerInstance.Send<NotificationMessage>(loggedInMessage);

            var msg = new ChangePageMessage(typeof(MainMenuViewModel));
            MessengerInstance.Send<ChangePageMessage>(msg);
        }