public static string GetSelectedKeyValue(ComboBoxEdit cmb, int rowLoai) { string temp = ""; string temp1 = ""; foreach (var p in cmb.SelectedItems) { temp += p.ToString(); } for (int i = 0; i < rowLoai; i++) { string key = cmb.GetKeyValue(i).ToString().Trim(); if (temp.Contains(key)) if (temp1 == "") { temp1 += key; } else temp1 = temp1 + ";" + key; } return temp1; }