protected override void OnClosed(EventArgs e)
        {
            _source?.RemoveHook(HwndHook);
            HotKeyApi.UnregisterHotKey(_windowHandle, HotKeyApi.ActivateHotKeyId);

            base.OnClosed(e);
        }
        protected override void OnSourceInitialized(EventArgs e)
        {
            base.OnSourceInitialized(e);

            _windowHandle = new WindowInteropHelper(this).Handle;
            _source       = HwndSource.FromHwnd(_windowHandle);
            _source?.AddHook(HwndHook);

            HotKeyApi.RegisterHotKey(_windowHandle, HotKeyApi.ActivateHotKeyId, HotKeyApi.ModAlt, HotKeyApi.ZKey);
        }