AvaloniaMvvmDesktopViewsFactory 1.0.6

AvaloniaMvvmDesktopViewsFactory (EN)

A library for building desktop applications on the .NET platform using the AvaloniaUI framework, a centralized view factory, and the MVVM architectural pattern.

Description

AvaloniaMvvmDesktopViewsFactory is an infrastructure library for .NET desktop applications that use AvaloniaUI and follow the MVVM architecture. It provides a centralized mechanism for creating, displaying, and closing window-views (Window) based on their corresponding view models (ViewModel), eliminating tight coupling between layers.

The library adheres strictly to the MVVM pattern and is structured as a dependency-injected service (DI). To use it, you must configure your DI container and add the Microsoft.Extensions.DependencyInjection package.

View–ViewModel association is performed via the [ViewFor] attribute or naming convention (MainViewModel ↔ MainView).

Features

• Creating the application's main window (MainWindow) from a given view model.
• Displaying modal and non-modal windows without explicit type references.
• Dialog support with return values (ShowDialogViewWithResultAsync).
• Safe window closing based on the associated view model’s unique identifier (UID).
• Automatic disposal of view models that implement IDisposable when the window closes.
• Support for multiple windows of the same type displayed simultaneously — each linked to a unique view model via its UID.
• Cached ViewModel → View resolution for better performance.

Requirements

• .NET 6.0 or .NET 8.0
• AvaloniaUI 11.3.5
• Microsoft.Extensions.DependencyInjection
• MVVM architecture with DI container support

License

MIT License

📦 Usage

1. Create a desktop application targeting .NET 6.0 or .NET 8.0 using the template:

   Avalonia .NET MVVM App (AvaloniaUI)

2. Install NuGet packages:

   dotnet add package Microsoft.Extensions.DependencyInjection
   dotnet add package AvaloniaMvvmDesktopViewsFactory
   

3. Modify the Program class as follows:

   internal sealed class Program
   {
       // This is the entry point of the application for dependencies.
       public static IServiceProvider ServiceProvider { get; private set; } = default!;
   
       // Initialization code. Don't use any Avalonia, third-party APIs or any
       // SynchronizationContext-reliant code before AppMain is called: things aren't initialized
       // yet and stuff might break.
       [STAThread]
       public static void Main(string[] args)
       {
           // Create a service collection and configure services.
           var services = new ServiceCollection();
           ConfigureServices(services);
           ServiceProvider = services.BuildServiceProvider();
   
           // Start the Avalonia application.
           BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
       }
   
       // Avalonia configuration, don't remove; also used by visual designer.
       public static AppBuilder BuildAvaloniaApp()
           => AppBuilder.Configure<App>()
               .UsePlatformDetect()
               .WithInterFont()
               .LogToTrace()
               .UseReactiveUI();
   
       // Configures the services for dependency injection.
       private static void ConfigureServices(IServiceCollection services)
       {
           services.AddSingleton<IGuidProvider, GuidProvider>();
   
   
           // Register the ViewsFactory with the service provider.
           services.AddSingleton<IViewsFactory>(provider =>
           {
               // Initializing the view factory.
               var guidProvider = provider.GetRequiredService<IGuidProvider>();
               var viewAssembly = typeof(MainWindowView).Assembly;
               var viewModelAssembly = typeof(MainWindowViewModel).Assembly;
               var viewsFactory = new ViewsFactory(guidProvider, viewAssembly, viewModelAssembly);
   
               // Registering additional assemblies the Views and ViewModels.
               //viewsFactory.RegisterAssemblies(otheViewAssembly, otheViewModelAssembly);
   
               return viewsFactory;
           });
   
           // Register your ViewModels here.
           services.AddTransient<MainWindowViewModel>();
       }
   }
   

4. Modify the App class as follows:

   public partial class App : Application
   {
       public override void Initialize()
       {
           AvaloniaXamlLoader.Load(this);
       }
   
       public override void OnFrameworkInitializationCompleted()
       {
           if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
           {
               var viewsFactory = Program.ServiceProvider.GetRequiredService<IViewsFactory>();
               var mainViewModel = Program.ServiceProvider.GetRequiredService<MainWindowViewModel>();
               desktop.MainWindow = viewsFactory.CreateMainView(mainViewModel);
   
               desktop.Exit += (_, _) =>
               {
                   Debug.WriteLine("Application exiting.");
   
                   // Dispose of the views factory if it implements IDisposable.
                   if (viewsFactory is IDisposable disposableFactory)
                   {
                       Debug.WriteLine("Disposing views factory.");
                       disposableFactory.Dispose();
                   }
               };
           }
   
           base.OnFrameworkInitializationCompleted();
       }
   }
   

5. Modify the ViewModelBase class as follows:

   public class ViewModelBase : ReactiveObject, IUnique
   {
       public Guid Uid
       {
           get => _uid;
           set
           {
               if (_uid != Guid.Empty)
                   throw new InvalidOperationException($"[{nameof(ViewModelBase)}] Uid is already assigned and cannot be changed.");
   
               if (value == Guid.Empty)
                   throw new ArgumentException($"[{nameof(ViewModelBase)}] Uid must not be empty.", nameof(value));
   
               this.RaiseAndSetIfChanged(ref _uid, value);
           }
       }
       public Guid _uid;
   }
   

6. Minimal working pattern for MainWindowViewModel:

   public class MainWindowViewModel : ViewModelBase, IDisposable
   {
       private readonly IViewsFactory _viewsService;
       private readonly CompositeDisposable _disposables = new();
       private bool _isDisposed;
   
       public MainWindowViewModel(IViewsFactory viewsService)
       {
           _viewsService = viewsService ?? throw new ArgumentNullException(nameof(viewsService));
       }
   
       public void Dispose()
       {
           if (_isDisposed) return;
   
           // Release of all subscriptions.
           _disposables.Dispose();
   
           _isDisposed = true;
   
           Debug.WriteLine($"[{nameof(MainWindowViewModel)}] The Dispose method is complete for {nameof(MainWindowViewModel)}, Guid {Uid}.");
       }
   }
   

7. Now you no longer need to hold a direct reference to a window instance in order to open or close a view — this can be done via the factory, for example:

   var questionBoxViewModel = new QuestionBoxViewModel("Are you sure ...?", "Question");
   var result = await _viewsService.ShowDialogViewWithResultAsync<QuestionBoxViewModel, QuestionBoxResult>(questionBoxViewModel);
   
   if (result == QuestionBoxResult.Ok)
   {
   }
   else
   {
   }
   

   You can also explore the code of the demo application or reach out to the author with a question.

AvaloniaMvvmDesktopViewsFactory (RU)

** Библиотека для построения десктопных приложений на платформе .NET с использованием фреймворка AvaloniaUI, централизованной фабрики представлений и архитектурного паттерна MVVM.**

Описание

AvaloniaMvvmDesktopViewsFactory — это инфраструктурная библиотека для .NET-приложений с графическим интерфейсом, использующих AvaloniaUI и архитектуру MVVM. Она предоставляет централизованный механизм создания, отображения и закрытия окон-представлений (Window), ассоциированных с соответствующими моделями представления (ViewModel), устраняя жёсткие зависимости между слоями приложения.

Библиотека ориентирована на строгое соблюдение паттерна MVVM и организована в виде сервиса, интегрируемого через механизм внедрения зависимостей (DI). Для использования требуется предварительная настройка контейнера и установка пакета Microsoft.Extensions.DependencyInjection.

Сопоставление представлений с моделями осуществляется с помощью атрибута [ViewFor] либо на основе соглашения об именовании (MainViewModel ↔ MainView).

Возможности

• Создание основного окна приложения (MainWindow) по заданной модели представления.
• Отображение немодальных и модальных окон без необходимости прямого указания типа представления.
• Поддержка диалоговых окон с возвращаемым результатом (ShowDialogViewWithResultAsync).
• Безопасное закрытие окна, связанного с конкретной моделью представления, с учётом уникального идентификатора (UID).
• Автоматическое освобождение ресурсов моделей, реализующих IDisposable, при закрытии окна.
• Поддержка одновременного отображения нескольких окон одного типа: каждое окно связано со своей моделью и управляется независимо благодаря системе UID.
• Кэширование сопоставлений ViewModel → View для повышения производительности.

Требования

• .NET 6.0 или .NET 8.0
• AvaloniaUI 11.3.5
• Microsoft.Extensions.DependencyInjection
• MVVM-архитектура с поддержкой внедрения зависимостей (DI)

Лицензия

MIT License

📦 Использование

1. Создайте десктопное приложение под .NET 6.0 или .NET 8.0, используя шаблон:

   Avalonia .NET MVVM App (AvaloniaUI)

2. Установите NuGet-пакеты:

   dotnet add package Microsoft.Extensions.DependencyInjection
   dotnet add package AvaloniaMvvmDesktopViewsFactory
   

3. Измените класс Program следующим образом:

   internal sealed class Program
   {
       // This is the entry point of the application for dependencies.
       public static IServiceProvider ServiceProvider { get; private set; } = default!;
   
       // Initialization code. Don't use any Avalonia, third-party APIs or any
       // SynchronizationContext-reliant code before AppMain is called: things aren't initialized
       // yet and stuff might break.
       [STAThread]
       public static void Main(string[] args)
       {
           // Create a service collection and configure services.
           var services = new ServiceCollection();
           ConfigureServices(services);
           ServiceProvider = services.BuildServiceProvider();
   
           // Start the Avalonia application.
           BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
       }
   
       // Avalonia configuration, don't remove; also used by visual designer.
       public static AppBuilder BuildAvaloniaApp()
           => AppBuilder.Configure<App>()
               .UsePlatformDetect()
               .WithInterFont()
               .LogToTrace()
               .UseReactiveUI();
   
       // Configures the services for dependency injection.
       private static void ConfigureServices(IServiceCollection services)
       {
           services.AddSingleton<IGuidProvider, GuidProvider>();
   
   
           // Register the ViewsFactory with the service provider.
           services.AddSingleton<IViewsFactory>(provider =>
           {
               // Initializing the view factory.
               var guidProvider = provider.GetRequiredService<IGuidProvider>();
               var viewAssembly = typeof(MainWindowView).Assembly;
               var viewModelAssembly = typeof(MainWindowViewModel).Assembly;
               var viewsFactory = new ViewsFactory(guidProvider, viewAssembly, viewModelAssembly);
   
               // Registering additional assemblies the Views and ViewModels.
               //viewsFactory.RegisterAssemblies(otheViewAssembly, otheViewModelAssembly);
   
               return viewsFactory;
           });
   
           // Register your ViewModels here.
           services.AddTransient<MainWindowViewModel>();
       }
   }
   

4. Измените класс App следующим образом:

   public partial class App : Application
   {
       public override void Initialize()
       {
           AvaloniaXamlLoader.Load(this);
       }
   
       public override void OnFrameworkInitializationCompleted()
       {
           if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
           {
               var viewsFactory = Program.ServiceProvider.GetRequiredService<IViewsFactory>();
               var mainViewModel = Program.ServiceProvider.GetRequiredService<MainWindowViewModel>();
               desktop.MainWindow = viewsFactory.CreateMainView(mainViewModel);
   
               desktop.Exit += (_, _) =>
               {
                   Debug.WriteLine("Application exiting.");
   
                   // Dispose of the views factory if it implements IDisposable.
                   if (viewsFactory is IDisposable disposableFactory)
                   {
                       Debug.WriteLine("Disposing views factory.");
                       disposableFactory.Dispose();
                   }
               };
           }
   
           base.OnFrameworkInitializationCompleted();
       }
   }
   

5. Измените класс ViewModelBase следующим образом:

   public class ViewModelBase : ReactiveObject, IUnique
   {
       public Guid Uid
       {
           get => _uid;
           set
           {
               if (_uid != Guid.Empty)
                   throw new InvalidOperationException($"[{nameof(ViewModelBase)}] Uid is already assigned and cannot be changed.");
   
               if (value == Guid.Empty)
                   throw new ArgumentException($"[{nameof(ViewModelBase)}] Uid must not be empty.", nameof(value));
   
               this.RaiseAndSetIfChanged(ref _uid, value);
           }
       }
       public Guid _uid;
   }
   

6. Минимальный шаблон реализации MainWindowViewModel:

   public class MainWindowViewModel : ViewModelBase, IDisposable
   {
       private readonly IViewsFactory _viewsService;
       private readonly CompositeDisposable _disposables = new();
       private bool _isDisposed;
   
       public MainWindowViewModel(IViewsFactory viewsService)
       {
           _viewsService = viewsService ?? throw new ArgumentNullException(nameof(viewsService));
       }
   
       public void Dispose()
       {
           if (_isDisposed) return;
   
           // Release of all subscriptions.
           _disposables.Dispose();
   
           _isDisposed = true;
   
           Debug.WriteLine($"[{nameof(MainWindowViewModel)}] The Dispose method is complete for {nameof(MainWindowViewModel)}, Guid {Uid}.");
       }
   }
   

7. Теперь для открытия и закрытия представлений вам не нужно иметь ссылку экземпляр окна, вы можете это делать через обращения к фабрике подобным образом:

   var questionBoxViewModel = new QuestionBoxViewModel("Вы уверены ... ?", "Вопрос.");
   var result = await _viewsService.ShowDialogViewWithResultAsync<QuestionBoxViewModel, QuestionBoxResult>(questionBoxViewModel);
   
   if (result == QuestionBoxResult.Ok)
   {
   }
   else
   {
   }
   

Вы также можете изучить код демонстрационного приложения или обратиться к автору с вопросом.

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