📄 src/App/App.axaml.cs
using Avalonia;
using Avalonia.Controls.ApplicationLifetimes;
using Avalonia.Markup.Xaml;
using Microsoft.Extensions.DependencyInjection;
using MMirror.App.ViewModels;
using MMirror.App.Views;

namespace MMirror.App;

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

    public override void OnFrameworkInitializationCompleted()
    {
        var collection = new ServiceCollection();
        collection.AddViewModels();

        var services = collection.BuildServiceProvider();

        DataTemplates.Add(new ViewLocator(services));
        var vm = services.GetRequiredService<MainViewModel>();

        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
        {
            desktop.MainWindow = new MainWindow { DataContext = vm };
        }
        else if (ApplicationLifetime is ISingleViewApplicationLifetime singleView)
        {
            singleView.MainView = new MainView { DataContext = vm };
        }

        base.OnFrameworkInitializationCompleted();
    }
}