private void SearchClick(object sender, RoutedEventArgs e) { foreach (CollectionItem item in items) { item.Visibility = string.IsNullOrWhiteSpace(tbSearch.Text) ? Visibility.Visible : (manager.MatchSearch(item, tbSearch.Text) ? Visibility.Visible : Visibility.Collapsed); } pnlSearch.BorderBrush = new SolidColorBrush(string.IsNullOrWhiteSpace(tbSearch.Text) ? Color.FromRgb(171, 173, 179) : Colors.Green); }