configuring-avalonia-dependency-injection

name	configuring-avalonia-dependency-injection
description	Configures GenericHost and Dependency Injection in AvaloniaUI applications. Use when setting up DI container, registering services, or implementing IoC patterns in AvaloniaUI projects.

6.6 Dependency Injection and GenericHost Usage

Apply the same GenericHost pattern in AvaloniaUI as in WPF

Project Structure

The templates folder contains a .NET 9 AvaloniaUI project example.

templates/
├── AvaloniaDISample.App/           ← Avalonia Application Project
│   ├── Views/
│   │   ├── MainWindow.axaml
│   │   └── MainWindow.axaml.cs
│   ├── App.axaml
│   ├── App.axaml.cs
│   ├── Program.cs
│   ├── GlobalUsings.cs
│   └── AvaloniaDISample.App.csproj
└── AvaloniaDISample.ViewModels/    ← ViewModel Class Library (UI framework independent)
    ├── MainViewModel.cs
    ├── GlobalUsings.cs
    └── AvaloniaDISample.ViewModels.csproj

App.axaml.cs Example:

// App.axaml.cs
namespace MyApp;

using Avalonia;
using Avalonia.Controls.ApplicationLifetimes;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

public partial class App : Application
{
    private IHost? _host;

    public override void Initialize()
    {
        AvaloniaXamlLoader.Load(this);
    }

    public override void OnFrameworkInitializationCompleted()
    {
        // Create GenericHost and register services
        _host = Host.CreateDefaultBuilder()
            .ConfigureServices((context, services) =>
            {
                // Register services
                services.AddSingleton<IUserRepository, UserRepository>();
                services.AddSingleton<IUserService, UserService>();
                services.AddTransient<IDialogService, DialogService>();

                // Register ViewModels
                services.AddTransient<MainViewModel>();

                // Register Views
                services.AddSingleton<MainWindow>();
            })
            .Build();

        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
        {
            desktop.MainWindow = _host.Services.GetRequiredService<MainWindow>();
        }

        base.OnFrameworkInitializationCompleted();
    }
}