private static async void SetGlowingForActiveWindow() { await Task.Delay(2500); var hWnd = User32.GetForegroundWindow(); var appHandles = Application.Current.Windows .OfType <Window>() .Select(x => PresentationSource.FromVisual(x) as HwndSource) .Where(x => x != null) .Select(x => x.Handle) .ToArray(); if (appHandles.All(x => x != hWnd)) { var external = new ExternalWindow(hWnd); var chrome = new WindowChrome(); chrome.Attach(external); } }