Frame.navigate和NagivationService不起作用

Question

I don't know why Frame.Navigate and NavigationService don't work.

Here my following code, MainPage.xaml :

<Grid>
    <ContentControl Content="{Binding CurrentViewModel}" />

    <Button
        Command="{Binding ConnexionViewCommand}"
        x:Name="Connexion_button" 
        HorizontalAlignment="Left" 
        Margin="90,308,0,0"
        Content="Login" 
        VerticalAlignment="Top" 
        Width="282"/>
    <Button 
        Command="{Binding InscriptionViewCommand}"
        x:Name="Create_account" 
        HorizontalAlignment="Left" 
        Margin="90,446,0,0"
        Content="Create Account" 
        VerticalAlignment="Top" 
        Width="282"/>
</Grid>

MainViewModel.cs

public class MainViewModel : ViewModelBase
{
    private ViewModelBase _currentViewModel;

    readonly static ConnexionViewModel _ConnexionViewModel = new ConnexionViewModel();
    readonly static InscriptionViewModel _InscriptionViewModel = new InscriptionViewModel();
    readonly static MainPageViewModel _MainPageViewModel = new MainPageViewModel();


    public ViewModelBase CurrentViewModel
    {
        get
        {
            return _currentViewModel;
        }
        set
        {
            if (_currentViewModel == value)
                return;
            _currentViewModel = value;
            RaisePropertyChanged("CurrentViewModel");
        }
    }
    public ICommand ConnexionViewCommand { get; private set; }
    public ICommand InscriptionViewCommand { get; private set; }

    public MainViewModel()
    {
        CurrentViewModel = MainViewModel._MainPageViewModel;
        ConnexionViewCommand =  new RelayCommand(() => ExecuteConnexionViewCommand());
        InscriptionViewCommand = new RelayCommand(() => ExecuteInscriptionViewCommand());
    }

    private void ExecuteConnexionViewCommand()
    {
        Frame.Navigate(typeof(ConnexionView));
        NavigationService.Navigate(new Uri("/ConnexionView.xaml", UriKind.Relative));
        MessageBox.Show("CONNEXION");
    }

    private void ExecuteInscriptionViewCommand()
    {
        Frame.Navigate(typeof(InscriptView));
        NavigationService.Navigate(new Uri("/InscriptionView.xaml", UriKind.Relative));
        MessageBox.Show("REGISTER");
    }

I have this following error for my Frame.navigate : Cannot Convert System.String to System.Uri.

For my NavigationService.Navigate : An object reference is required for the property. The method or the non-static field "NavigationService.Navigate (Uri)

Thanks for your help.

Answer 1

You are mixing two different things together

This NavigationService.Navigate(new Uri("/ConnexionView.xaml", UriKind.Relative)); is common approach in Windows Phone 8.0 and 8.1 Silverlight.

This is approach used at Windows Phone 8.1 : Frame.Navigate(typeof(ConnexionView));

In your case Frame.Navigate is not an option, just delete that line.

Answer 2

您不能将Frame.nagivate和NavigationService.Navigate混合在一起。