private void CBLetter_SelectedIndexChanged(object sender, EventArgs e) { isNotChange = false; cbFamil.Items.Clear(); try { List <string> list = new List <string>(); list = tc.getFamilPupils(CBClass.Text, CBLetter.Text); for (int i = 0; i < list.Count; i++) { cbFamil.Items.Add(list[i]); } cbFamil.SelectedIndex = 0; } catch (Exception ex) { MessageBox.Show("Не удалось получить список\r\n" + ex.Message, "Ошибка", MessageBoxButtons.OK, MessageBoxIcon.Error); } }