[BUG] System.ArgumentException: Page to remove must be contained on this Navigation Page about prism

[carlosxjose]

You have to do this at MauiProgram.cs

.UsePrism(prism =>
{
    prism.RegisterTypes(cr =>
    {
        //cr.RegisterForNavigation<NavigationPage>();//This is not necesarry
        cr.RegisterForNavigation<MainPage>();
    });
    prism.CreateWindow(async (container, navigation) =>
    {
        var result = await navigation.NavigateAsync($"/{nameof(NavigationPage)}/{nameof(MainPage)}");
    });
})

At App.xaml.cs

    public App()
    {
        InitializeComponent();

        //MainPage = new AppShell();//This is not necesarry
    }

And voilá

[RobFrancisAu]

Thanks you @carlosxjose, turns out (per your comment) the issue in my main project was the registration of the NavigationPage

.UsePrism(prism =>
{
    prism.RegisterTypes(cr =>
    {
        cr.RegisterForNavigation<NavigationPage>(); // THIS IS THE PROBLEM
    });
    prism.CreateWindow(async (container, navigation) =>
    {
        var result = await navigation.NavigateAsync($"/{nameof(NavigationPage)}/{nameof(MainPage)}");
    });
})

This has fixed the crashing but has also caused a styling issues. I am currently styling like this, which worked in Xamarin

<Style TargetType="NavigationPage">
        <Setter Property="BarBackgroundColor" Value="{DynamicResource NavigationBarColour}" />
        <Setter Property="BarTextColor" Value="{DynamicResource NavigationBarTextColour}" />
</Style>

The DynamicResource allowed me to switch between multiple themes at runtime. I understand this is a completely seperate issue, but this did work prior to 9.0.401-pre.

[dansiegel]

@RobFrancisAu Prism does not directly use the NavigationPage but rather uses a customized PrismNavigationPage. You can simply update your style to match either of the following

<Style TargetType="NavigationPage" ApplyToDerivedTypes="True">
</Style>

<Style TargetType="prism:PrismNavigationPage">
</Style>

[RobFrancisAu]

Fantastic, thanks @dansiegel ! That did the trick.