private void ImportPackage_Click(object sender, RoutedEventArgs e) { AppearanceManager.Current.ThemeSource = new Link { DisplayName = "light", Source = AppearanceManager.LightThemeSource }.Source; Preview.Text = string.Empty; oldVal = PackageTypes.SelectedIndex; ImportPackage pack = new ImportPackage(); pack.ShowDialog(); PackageTypes.ItemsSource = dirInfo.EnumerateDirectories(); AppearanceManager.Current.ThemeSource = new Link { DisplayName = "dark", Source = AppearanceManager.DarkThemeSource }.Source; }