Agent skill · software engineering · github
winui3-migration-guide
UWP-to-WinUI 3 migration reference. Maps legacy UWP APIs to correct Windows App SDK equivalents with before/after code snippets. Covers namespace changes, threading (CoreDispatcher to DispatcherQueue), windowing (CoreWindow to AppWindow), dialogs, pickers, sharing, printing, background tasks, and the most common Copilot code generation mistakes.
Why this skill is useful
Provides specific mappings and code snippets for migrating UWP apps to WinUI 3 that the AI wouldn't reliably generate on its own.
What it needs
About 4k tokens when loaded. Last updated 2026-08-07. 37,534 stars on the source repository.
What this skill does
WinUI 3 Migration Guide Use this skill when migrating UWP apps to WinUI 3 / Windows App SDK, or when verifying that generated code uses correct WinUI 3 APIs instead of legacy UWP patterns. --- Namespace Changes All Windows.UI.Xaml. namespaces move to Microsoft.UI.Xaml.: UWP Namespace WinUI 3 Namespace -------------- ------------------- Windows.UI.Xaml Microsoft.UI.Xaml Windows.UI.Xaml.Controls Microsoft.UI.Xaml.Controls Windows.UI.Xaml.Media Microsoft.UI.Xaml.Media Windows.UI.Xaml.Input Microsoft.UI.Xaml.Input Windows.UI.Xaml.Data Microsoft.UI.Xaml.Data Windows.UI.Xaml.Navigation Microsoft.UI.Xaml.Navigation Windows.UI.Xaml.Shapes Microsoft.UI.Xaml.Shapes Windows.UI.Composition Microsoft.UI.Composition Windows.UI.Input Microsoft.UI.Input Windows.UI.Colors Microsoft.UI.Colors Windows.UI.Text Microsoft.UI.Text Windows.UI.Core Microsoft.UI.Dispatching (for dispatcher) --- Top 3 Most Common Copilot Mistakes 1. ContentDialog Without XamlRoot 2. MessageDialog Instead of ContentDialog 3. CoreDispatcher Instead of DispatcherQueue --- Windowing Migration Window Reference Window Management UWP API WinUI 3 API --------- ------------- ApplicationView.TryResizeView() AppWindow.Resize() AppWindow.TryCreateAsync() AppWindow.Create() AppWindow.TryShowAsync() AppWindow.Show() AppWindow.TryConsolidateAsync() AppWindow.Destroy() AppWindow.RequestMoveXxx() AppWindow.Move() AppWindow.GetPlacement() AppWindow.Position property AppWindow.RequestPresentation() AppWindow.SetPresenter() Title Bar UWP API WinUI 3 API --------- ------------- CoreApplicationViewTitleBar AppWindowTitleBar CoreApplicationView.TitleBar.ExtendViewIntoTitleBar AppWindow.TitleBar.ExtendsContentIntoTitleBar --- Dialogs and Pickers Migration File/Folder Pickers Threading Migration UWP Pattern WinUI 3 Equivalent ------------- ------------------- CoreDispatcher.RunAsync(priority, callback) DispatcherQueue.TryEnqueue(priority, callback) Dispatcher.HasThreadAccess DispatcherQueue.HasThreadAccess CoreDispatcher.ProcessEvent …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills github/winui3-migration-guide