using Avalonia.Controls.ApplicationLifetimes; using Avalonia.Markup.Xaml; namespace Avalonia.DesignerSupport.TestApp { public class App : Application { public override void Initialize() { AvaloniaXamlLoader.Load(this); } public override void OnFrameworkInitializationCompleted() { if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop) desktop.MainWindow = new MainWindow(); base.OnFrameworkInitializationCompleted(); } } }