private void Mnu_PurgeElements_Click(object sender, RoutedEventArgs e) { CarboGroup carboGroup = (CarboGroup)dgv_Overview.SelectedItem; if (carboGroup != null) { if (carboGroup.AllElements.Count > 0) { MessageBoxResult result = MessageBox.Show("Do you really want to remove all elements from this collection? This action is can NOT be undone", "Warning", MessageBoxButton.YesNo, MessageBoxImage.Stop); if (result == MessageBoxResult.Yes) { CarboLifeProject.PurgeElements(carboGroup); } } else { MessageBoxResult result = MessageBox.Show("This collection contains no elements", "Warning", MessageBoxButton.YesNo, MessageBoxImage.Stop); } } SortData(); }