marb2000

public static class WindowExtensions
    {
        public static void SetSize(this Window window, int width, int height)
        {
            // To set the size you need to wrap the XAML window in AppWindow
            var hwnd = WinRT.Interop.WindowNative.GetWindowHandle(window);
            var windowsId = Microsoft.UI.Win32Interop.GetWindowIdFromWindow(hwnd);
            var appWindow = Microsoft.UI.Windowing.AppWindow.GetFromWindowId(windowsId);

            // Notice that AppWindow uses raw pixels because it's a low level API.