private void AreaComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e) { var selItem = AreaComboBox.SelectedItem as Area; if (selItem != null) { var orgs = _catMgr.GetOrgatizations(selItem.SOATO); OKPOComboBox.Items.Clear(); orgs.ToList().ForEach(x => OKPOComboBox.Items.Add(x)); } }