過濾時，一次可以按多個單號過濾

        private void dgvPO_ColumnFilterChanged(object sender, EventArgs e)
        {
            if (ColCode.FilterInfo.Value != null && string.IsNullOrEmpty(ColCode.FilterInfo.Value.ToString()) == false)
            {
                StringBuilder codes = new StringBuilder();
                List<string> codeList = ColCode.FilterInfo.Value.ToString().Split(',').ToList();
                foreach (string code in codeList)
                {
                    if (codes.Length == 0)
                    {
                        codes.AppendFormat("'{0}'", code);
                    }
                    else
                    {
                        codes.AppendFormat(",'{0}'", code);
                    }
                }
                if (codeList.Count > 1)
                {
                    StringBuilder activeFilterString = new StringBuilder();
                    activeFilterString.Append(dgvPO.ActiveFilterString.Replace(ColCode.FilterInfo.FilterString, string.Empty));
                    if (activeFilterString.Length == 0)
                    {
                        activeFilterString.AppendFormat("[{0}] in ({1})", ColCode.FieldName, codes.ToString());
                    }
                    else
                    {
                        activeFilterString.AppendFormat(" and [{0}] in ({1})", ColCode.FieldName, codes.ToString());
                    }
                    dgvPO.ActiveFilterString = activeFilterString.ToString();
                }
            }
        }