public ExampleViewModel(NavigationService navigationService, MessagingService messagingService)
        {
            Message = "Example text 2";
            this.navigationService = navigationService;
            this.messagingService = messagingService;

            messagingService.Register();

            NavigateBackCommand = new RelayCommand(NavigateBackExecute);
        }
        public MainViewModel(NavigationService navigationService, NetworkService networkService,
                                StorageService storageService, MessagingService messagingService)
        {
            this.navigationService = navigationService;
            this.storageService = storageService;
            this.networkService = networkService;
            this.messagingService = messagingService;
            
            //Message = "Dynamic text 1";
            Message = networkService.IsOnline().ToString();
            //storageService.save_myFile("hola");
            //storageService.save_myFile("que");
            //storageService.save_myFile("tal");

            CreateFileCommand = new RelayCommand(CreateFileExecute);
            ReadFileCommand = new RelayCommand(ReadFileExecute);
            ClearFileCommand = new RelayCommand(ClearFileExecute);
            NavigateToCommand = new RelayCommand(NavigateToExample);
            NumberMessageCommand = new RelayCommand(NumberMessageExecute);
        }