Mystify/Mystify/App.axaml.cs

using Avalonia;
using Avalonia.Controls;
using Avalonia.Controls.ApplicationLifetimes;
using Avalonia.Markup.Xaml;
using LightweightIocContainer.Interfaces;
using Mystify.ViewModels;
using Mystify.Views;

namespace Mystify
{
    public class App : Application
    {
        private IIocContainer? _kernel;
        
        public override void Initialize() => AvaloniaXamlLoader.Load(this);

        public override void OnFrameworkInitializationCompleted()
        {
            if (Design.IsDesignMode)
                return;

            Bootstrapper bootstrapper = new();
            _kernel = bootstrapper.BootstrapKernel();
            
            if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktopStyleApplicationLifetime)
            {
                desktopStyleApplicationLifetime.MainWindow = new MainWindow
                {
                    DataContext = new MainWindowViewModel(),
                };
                desktopStyleApplicationLifetime.Exit += OnExit;
            }

            base.OnFrameworkInitializationCompleted();
        }

        private void OnExit(object? sender, ControlledApplicationLifetimeExitEventArgs args) => _kernel?.Dispose();
    }
}