Stale UWP Patterns

AI agents often generate UWP or WinUI 2 code when asked for WinUI 3. Use this page as a review checklist.

Migration Table

Scenario	Reject	Use
XAML namespace	`Windows.UI.Xaml.*`	`Microsoft.UI.Xaml.*`
Dialog	`Windows.UI.Popups.MessageDialog`	`ContentDialog` with `XamlRoot`
Dispatcher	`CoreDispatcher.RunAsync`	`DispatcherQueue.TryEnqueue`
Current window	`Window.Current`	Explicit `MainWindow` or window registry
Window management	`ApplicationView`, `CoreWindow`	`Microsoft.UI.Windowing.AppWindow`
Title bar	`CoreApplicationViewTitleBar`	`AppWindowTitleBar` or current title bar APIs
Share	Direct UWP `DataTransferManager`	Desktop interop with HWND where required
Print	Direct UWP `PrintManager`	Desktop interop with HWND where required
Background task	UWP `IBackgroundTask`	Desktop service/lifecycle/activation model
XAML tests	Normal unit test host for XAML	WinUI Unit Test App and `[UITestMethod]`
XAML Islands	Treat as WinUI 3	Treat as UWP XAML hosting path

Code Review Search

Run targeted searches in a source repo:

rg "Windows\.UI\.Xaml|CoreDispatcher|Window\.Current|ApplicationView|CoreWindow|MessageDialog|IBackgroundTask"

If any result appears, verify it is either intentionally historical/migration-only or replace it.

Dispatcher Example

DispatcherQueue.TryEnqueue(() =>
{
    StatusText.Text = "Done";
});

Dialog Example

var dialog = new ContentDialog
{
    Title = "Confirm",
    Content = "Continue?",
    PrimaryButtonText = "Continue",
    CloseButtonText = "Cancel",
    XamlRoot = this.Content.XamlRoot,
};
await dialog.ShowAsync();

Warning: Do not accept generated WinUI code until it passes this stale-UWP search.