winui-hello-world

Python WinUI 3 Hello World

This is the smallest WinUI 3 sample in the repository. It complements the Tic-Tac-Toe samples by showing only the setup required to:

• bootstrap the Windows App SDK;
• enter a single-threaded WinRT apartment;
• load a small XAML fragment;
• project raw XAML objects with project_as();
• pass a generated StackPanel directly to the base UIElement API;
• create and activate a Window;
• subscribe to Button.Click; and
• release projected objects before leaving the apartment.

The flow is intentionally comparable to PyWinRT's WinUI 3 Hello World, while using dynwinrt's generated bootstrap and lifetime APIs.

Prerequisites

• WinApp CLI 0.6.2 or newer;
• dynwinrt installed in the selected Python interpreter; and
• dynwinrt-codegen on PATH, or passed with -Codegen.

Run

winapp restore
.\generate.ps1 -Codegen ..\..\..\target\release\dynwinrt-codegen.exe

.\run.ps1 -Python C:\path\to\python.exe -Major 2 -Minor 3

winapp restore prepares the pinned SDK metadata and bootstrap binaries under .winapp\. generate.ps1 uses that metadata to generate Python bindings and copies the selected architecture's bootstrap DLL to .runtime\.

Major and Minor default to 2 and 3. They must exactly match the Windows App SDK product version represented by the metadata, bootstrap DLL, and installed runtime.

Use -Smoke to create the window and controls, update the text once, print python-winui-hello-ok, and exit automatically.

The runtime keeps a single owned reference to the WinUI XAML implementation DLL from its first use until process termination, including cleanup on MTA threads that outlive the UI apartment. This does not replace the sample's event unsubscription, projected object release, or balanced RoApartment. The DLL and its module-level static state are not unloaded when the window closes; in-process WinUI module unloading/hot replacement is not supported. See Python WinUI lifetime policy.