WPF Application Architecture

Purpose

WPF applications must remain maintainable as UI complexity grows. AIC uses MVVM, dependency injection and clear separation between UI and business logic.

Standard Layers

Desktop Shell
ViewModels
Application Services
Domain
Infrastructure

Composition Root

The WPF app startup configures services:

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

    protected override async void OnStartup(StartupEventArgs e)
    {
        _host = Host.CreateDefaultBuilder()
            .ConfigureServices((context, services) =>
            {
                services.AddApplication();
                services.AddInfrastructure(context.Configuration);
                services.AddSingleton<MainWindow>();
                services.AddTransient<MainViewModel>();
            })
            .Build();

        await _host.StartAsync();

        var mainWindow = _host.Services.GetRequiredService<MainWindow>();
        mainWindow.Show();
    }
}

Rules

• Views define layout and interaction.

• ViewModels expose state and commands.

• Application services perform use cases.

• Infrastructure handles persistence, files, devices and APIs.

• Domain contains business rules.

UI Thread Rule

Never block the UI thread with I/O or long-running CPU work.

Use async commands and progress state.

Error Handling

WPF applications must have:

• user-friendly error messages

• structured logs for diagnostics

• global exception handling

• retry or recovery for transient failures

• safe shutdown behaviour

Deployment Considerations

Document:

• packaging format

• installation route

• update route

• configuration location

• logs location

• user data location

• rollback or uninstall approach