private void ExtendView_Click(object sender, RoutedEventArgs e) { bool extend = ExtendView.IsChecked.Value; CoreApplication.GetCurrentView().TitleBar.ExtendViewIntoTitleBar = extend; EnableControls.Visibility = extend ? Visibility.Visible : Visibility.Collapsed; if (extend) { rootPage.AddCustomTitleBar(); } else { rootPage.RemoveCustomTitleBar(); } }