Feat winui

[NeverMorewd]

Summary

This PR introduces initial WinUI 3 support for AsyncNavigation.

Important

WinUI 3 support is currently under active development. APIs and behavior may still change before it is considered stable.

What’s included

WinUI 3 platform support

• Add the new AsyncNavigation.WinUI project
• Add dependency injection registration through AddNavigationSupport()
• Add WinUI RegionManager attached properties
• Add view caching, lifecycle, and navigation history support
• Add icon resolution and indicator host integration

Region adapters

• ContentControl
• ItemsControl and derived controls such as ListView
• TabView
• NavigationView
  • Menu-item navigation through Tag
  • Nested menu-item selection
  • Back navigation
  • Selected-item synchronization
  • Content stretching

Dialog and window support

• Add the default WinUI dialog container
• Support custom WinUI windows
• Support asynchronous dialog closing
• Dispatch window closing through each platform’s UI dispatcher to avoid re-entrant Closing behavior
• Keep WPF and Avalonia platform behavior consistent

WinUI sample

Add a complete Sample.WinUI project covering:

• Content regions
• Items regions
• Tab regions
• NavigationView regions
• Nested regions
• Custom region adapters
• Dialogs and custom windows
• Loading indicators
• Navigation history
• Delayed and error navigation scenarios

Documentation

• Add WinUI 3 to the English and Chinese README files
• Clearly mark WinUI 3 support as being in development
• Link to the WinUI sample project

Validation

• AsyncNavigation.WinUI builds successfully
• Sample.WinUI builds successfully
• AsyncNavigation.Wpf builds successfully
• AsyncNavigation.Avalonia builds successfully
• Unit tests: 135 passed, 2 skipped, 0 failed

Notes

WinUI 3 support is currently intended for evaluation and feedback. Please test it carefully before using it in production.