presence/Presence.Desktop/App.axaml.cs

using System;
using Avalonia;
using Avalonia.Controls.ApplicationLifetimes;
using Avalonia.Markup.Xaml;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Presence.Desktop.DI;
using Presence.Desktop.ViewModels;
using Presence.Desktop.Views;

namespace Presence.Desktop
{
    public partial class App : Application
    {
        public static IServiceProvider? ServiceProvider { get; private set; }
        public override void Initialize()
        {
            AvaloniaXamlLoader.Load(this);
        }

        public override void OnFrameworkInitializationCompleted()
        {
            var serviceCollection = new ServiceCollection();
            serviceCollection.AddCommonService();
            
            serviceCollection.AddLogging(builder => 
            {
                builder.AddConsole();
                builder.SetMinimumLevel(LogLevel.Debug);
            });

            ServiceProvider = serviceCollection.BuildServiceProvider();

            if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
            {
                desktop.MainWindow = new MainWindow()
                {
                    DataContext = new MainWindowViewModel(ServiceProvider),
                };
            }

            base.OnFrameworkInitializationCompleted();
        }

    }
}