windows-xaml-developer

Development

Expert guidance on building modern Windows apps with WinUI 3, WPF, and the MVVM pattern.

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Inspect the Agent Skill at https://github.com/majiayu000/claude-skill-registry/blob/HEAD/skills/data/windows-xaml-developer/SKILL.md and all supporting files. Report provenance, permissions, scripts, dependencies, and security risks. Propose an exact installation into .agents/skills/windows-xaml-developer, but wait for my approval before writing files or running scripts.

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Windows XAML Developer

Overview

This skill provides best practices, architectural patterns, and library recommendations for building high-quality Windows desktop applications using XAML-based frameworks (WinUI 3 and WPF). It emphasizes the Model-View-ViewModel (MVVM) pattern, Dependency Injection (DI), and modern C# features.

When to Use

When generating code for Windows desktop applications (WinUI 3, WPF, UWP).
When structuring a new Windows XAML project.
When implementing the MVVM pattern.
When troubleshooting XAML binding or UI responsiveness issues.

Core Principles

MVVM First: Always separate UI logic (View) from business logic (ViewModel). Avoid code-behind (.xaml.cs) except for pure UI concerns (e.g., window manipulation).
Dependency Injection: Use DI to manage services and ViewModels. Avoid static singletons for testability.
Responsive UI: Never block the UI thread. Use async/await for I/O and heavy computations.
Modern Tooling: Leverage Roslyn source generators (e.g., CommunityToolkit.Mvvm) to reduce boilerplate.

Recommended Tech Stack

Frameworks

Primary: WinUI 3 (Windows App SDK) - The modern, native UI stack for Windows. Best for new applications.
Secondary: WPF (.NET 8/9) - Mature, stable ecosystem. Best for complex enterprise apps or when specific third-party controls are needed.

Essential Libraries

Category	Library	Usage
MVVM	`CommunityToolkit.Mvvm`	Standard implementation for `ObservableObject`, `RelayCommand`, and Messenger.
Dependency Injection	`Microsoft.Extensions.DependencyInjection`	Industry-standard DI container.
Hosting/Lifecycle	`Microsoft.Extensions.Hosting`	Application bootstrap, logging, and configuration.
WPF UI Library	`MaterialDesignInXamlToolkit` or `MahApps.Metro`	(WPF Only) Modern styling and controls.
WinUI Helpers	`CommunityToolkit.WinUI`	Additional controls, helpers, and extensions for WinUI 3.

Project Structure

Organize the solution to enforce strict separation of concerns:

MyWindowsApp/
├── App.xaml                 # Application entry & DI composition root
├── Views/                   # XAML Windows, Pages, and UserControls
├── ViewModels/              # C# ViewModels (one per View)
├── Models/                  # Domain entities and data structures
├── Services/                # Business logic and data access interfaces/implementations
├── Converters/              # IValueConverter implementations
└── Assets/                  # Images, fonts, and resources