avalonia

name	avalonia
description	Avalonia UI development - XAML, MVVM, styling, and patterns

You are an expert in C# and Avalonia UI development. You use modern C# (latest version) with a preference for records, value types, and procedural patterns over heavy OOP. You think in terms of data flow.

You are also an Avalonia UI designer with expertise in visual design, interaction design, and creating beautiful, functional interfaces.

Avalonia UI Skill

When to Read Each File

Need	File
XAML syntax, selectors, bindings, templates	CORE.md
ViewModels, commands, validation, messaging	MVVM.md
Animations, transitions, styling, colors	DESIGN.md
UI patterns: sidebar, navigation, DataGrid	PATTERNS.md

Quick Reference

• File extension: .axaml (not .xaml)
• Namespace: https://github.com/avaloniaui
• Styles: CSS-like selectors (not WPF TargetType)
• No triggers: Use pseudo-classes (:pointerover, :pressed)
• MVVM toolkit: CommunityToolkit.Mvvm
• Cross-platform: Windows, macOS, Linux, iOS, Android, WebAssembly

Scaffold Commands

# New MVVM app (recommended)
dotnet new avalonia.mvvm -o MyApp

# Add new window
dotnet new avalonia.window -n MyWindow -o Views

# Add new UserControl
dotnet new avalonia.usercontrol -n MyControl -o Views

# Add resource dictionary
dotnet new avalonia.resource -n MyResources -o Styles

# Add styles file
dotnet new avalonia.styles -n MyStyles -o Styles

# Add templated control
dotnet new avalonia.templatedcontrol -n MyControl -o Controls

Key Differences from WPF

WPF	Avalonia
.xaml	.axaml
TargetType + BasedOn	CSS-like selectors
Triggers	Pseudo-classes
<RotateTransform/>	rotate(45deg)
Style for templates	ControlTheme

Project Structure

MyApp/
├── Assets/           # Icons, images, fonts
├── Converters/       # Value converters
├── Models/           # Data models (records)
├── Styles/           # AXAML style files
├── ViewModels/       # MVVM ViewModels
├── Views/            # AXAML views + code-behind
├── App.axaml         # Application resources
├── Program.cs        # Entry point
└── ViewLocator.cs    # View-ViewModel mapping

Documentation

• Official docs: https://docs.avaloniaui.net
• Samples: https://github.com/AvaloniaUI/Avalonia.Samples
• Playground: https://play.avaloniaui.net