sa/Stars Assistant/App.axaml.cs

using Avalonia;
using Avalonia.Controls.ApplicationLifetimes;
using Avalonia.Markup.Xaml;
using StarsAssistant.ViewModels;
using StarsAssistant.Views;
using Splat;
using StarsAssistant.Services;

namespace StarsAssistant;

public partial class App : Application
{
    public override void Initialize()
    {
        AvaloniaXamlLoader.Load(this);
    }

    public override void OnFrameworkInitializationCompleted()
    {
        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
        {
            Game game = new(desktop.Args);
            game.RegisterServicesForGame();

            desktop.MainWindow = new MainWindow
            {
                DataContext = new MainWindowViewModel(),
            };

            base.OnFrameworkInitializationCompleted();

            game.StartBackgroundServices();
        }
        else
        {
            throw new InvalidOperationException("This app supports only Desktop mode.");
        }
    }
}