Lifter.Avalonia 2.0.1

Lifter.Avalonia

Avalonia UI 12 integration for Lifter, providing HostedApplication support with dependency injection, configuration, IHostedService lifecycle management, and the cross-platform IDialogService.

Features

✅ Dependency Injection - Full IServiceCollection and IServiceProvider support
✅ Configuration - IConfiguration with JSON, environment variables, and user secrets
✅ IHostedService Support - Background services managed by application lifecycle
✅ IDialogService - Native Avalonia dialog windows with full override points
✅ Cross-Platform - Proper Desktop (Window) and Mobile (SingleView) handling
✅ Splash Screen - Optional splash screen during initialization
✅ Customizable - Configurable window settings and lifecycle hooks

Installation

dotnet add package Lifter.Avalonia

Quick Start

1. Create Your Main View

using Avalonia.Controls;
using Lifter.Avalonia;

public partial class MainView : UserControl, IHostedView
{
    public MainView()
    {
        InitializeComponent();
    }
}

2. Create Your App Class

using Lifter.Avalonia;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

public class App : HostedApplication<MainView>
{
    protected override void ConfigureServices(
        IServiceCollection services, 
        IConfiguration configuration)
    {
        // Configure window settings
        services.ConfigureWindow(config =>
        {
            config.Title = "My Avalonia App";
            config.Width = 1024;
            config.Height = 768;
        });

        // Register your services
        services.AddSingleton<IMyService, MyService>();
        
        // Register background services
        services.AddHostedService<MyBackgroundService>();
    }
}

3. Update App.axaml

<avalonia:HostedApplication 
    xmlns="https://github.com/avaloniaui"
    xmlns:avalonia="using:Lifter.Avalonia"
    x:Class="MyApp.App">
</avalonia:HostedApplication>

Advanced Usage

Custom Initialization

Override OnHostInitializedAsync for custom initialization logic:

protected override async Task OnHostInitializedAsync()
{
    // Perform database migration, load cached data, etc.
    var dbContext = Services.GetRequiredService<AppDbContext>();
    await dbContext.Database.MigrateAsync();
}

Splash Screen

Override CreateSplashScreen to show a custom splash screen:

protected override Control? CreateSplashScreen()
{
    return new SplashScreenView();
}

Background Services

Implement IHostedService for long-running background tasks:

public class DataSyncService : IHostedService
{
    public Task StartAsync(CancellationToken cancellationToken)
    {
        // Start background task
        return Task.CompletedTask;
    }

    public Task StopAsync(CancellationToken cancellationToken)
    {
        // Clean up
        return Task.CompletedTask;
    }
}

// Register in ConfigureServices
services.AddHostedService<DataSyncService>();

Platform Support

• ✅ Desktop (Windows, macOS, Linux) - Creates a Window with your view
• ✅ Mobile (iOS, Android via .NET MAUI) - Direct view assignment
• ✅ .NET 10 — targets net10.0
• ✅ Avalonia 12.0

How It Works

Desktop vs Mobile

Desktop (IClassicDesktopStyleApplicationLifetime):

var mainWindow = new Window
{
    Content = mainView,  // Your view becomes window content
    Title = "App",
    Width = 1200,
    Height = 960
};
desktop.MainWindow = mainWindow;
mainWindow.Show();

Mobile (ISingleViewApplicationLifetime):

singleView.MainView = mainView;  // Direct view assignment

Initialization Sequence

1. Build Host - Create IHost with DI and configuration
2. Show Splash - Optional splash screen
3. Async Init - Run OnHostInitializedAsync on background thread
4. Setup View - Create Window (Desktop) or set MainView (Mobile) on UI thread
5. Start Services - Start all IHostedService instances

Architecture

HostedApplication<TMainView>
    ├── HostApplicationBuilder (Microsoft.Extensions.Hosting)
    ├── IServiceProvider (Dependency Injection)
    ├── IConfiguration (Configuration)
    └── HostManager (Lifter.Core - manages IHostedService lifecycle)

License

MIT - See LICENSE file for details

Related Packages

• Lifter.Core - Core abstractions, HostManager, and IDialogService interfaces
• Lifter.Maui - .NET MAUI integration for Lifter
• Lifter.Blazor - Blazor WebAssembly integration for Lifter

IDialogService

AvaloniaDialogService shows native Avalonia Window dialogs parented to the desktop main window.

Registration

// In ConfigureServices (App.cs)
services.AddAvaloniaDialogService();

Usage

public class MainView : UserControl, IHostedView
{
    private readonly IDialogService _dialogs;

    public MainView(IDialogService dialogs)
    {
        _dialogs = dialogs;
    }

    private async Task OnDeleteClicked()
    {
        var result = await _dialogs.ShowConfirmAsync(
            "Delete item",
            "Are you sure?",
            new DialogOptions { ButtonSet = DialogButtonSet.YesNo });

        if (result.Confirmed)
        {
            // delete logic
        }
    }
}

Custom Override

Subclass AvaloniaDialogService and register it to customise any aspect of the dialog window:

public class MyDialogService : AvaloniaDialogService
{
    // Override to change which window owns the dialog
    protected override Window? GetOwnerWindow() { ... }

    // Override to fully restyle the dialog window
    protected override Window BuildDialogWindow(string title, DialogOptions options) { ... }

    // Override to change button layout
    protected override Panel BuildButtonPanel(DialogOptions options,
        TaskCompletionSource<DialogResult> tcs, Window dialog) { ... }
}

// Register the custom implementation
services.AddAvaloniaDialogService<MyDialogService>();