Navigate to page on start in .NET Maui app

Question

Seems like a simple question, but I haven't been able to find a simple answer. Essentially I want to choose which page in the app to start on based on some stored state. I added a GoToAsync call in the AppShell constructor, but this didn't work--which makes sense because the AppShell hasn't been fully constructed yet.

I found this answer, but it feels like it kind of skirts around the issue:

Maui AppShell - Navigate on Open

Where is the best place to inject some code that will run once on startup and can successfully navigate a .NET Maui app to a chosen page?

Answer 1

After playing around with overrides, it seems like overriding Application.OnStart works! Shell.Current is set at this point and navigation works.

Here's additional code that allows for asynchronous initialization and uses a Loading Page until the initialization is complete:

using MyApp.Services;
using MyApp.UI;

namespace MyApp;

public partial class App : Application
{
    ConfigurationProviderService m_configProvider;

    public App(ConfigurationProviderService configProvider)
    {
        m_configProvider = configProvider;

        InitializeComponent();

        MainPage = new LoadingPage();
    }

    protected override void OnStart()
    {
        var task = InitAsync();

        task.ContinueWith((task) =>
        {
            MainThread.BeginInvokeOnMainThread(() =>
            {
                MainPage = new AppShell();

                // Choose navigation depending on init
                Shell.Current.GoToAsync(...);
            });
        });

        base.OnStart();
    }

    private async Task InitAsync()
    {
        await m_configProvider.InitAsync();
    }
}