private void ComboxTenCDCoSan_Load(object sender, EventArgs e) { BUSGiaoVien a = new BUSGiaoVien(); DataTable dt = a.TenCDCombobox(); dt.Columns.Add("tencd", typeof(string)); dt.Dispose(); cbxTenCD.ValueMember = "tencd"; cbxTenCD.DataSource = dt; }