/// <summary>
        /// Occurs when the Control gets focus.
        /// </summary>
        ///
        /// <param name="e">The <see cref="T:System.Windows.RoutedEventArgs" /> that contains the event data.</param>
        ///
        /// <seealso cref="M:System.Windows.FrameworkElement.OnGotFocus(RoutedEventArgs)"/>
        protected override void OnGotFocus(RoutedEventArgs e)
        {
            try
            {
                if (_renderWindow != null)
                {
                    IntPtr hWnd = _renderWindow.GetGenericWindowId();

                    if (IntPtr.Zero != hWnd)
                    {
                        Win32.SetFocus(hWnd);
                    }
                }
            }
            catch (Exception ex)
            {
                log.ErrorException("OnGotFocus()", ex);
            }

            base.OnGotFocus(e);
        }