动态循环添加DataGrid绑定列

/////////动态添加扩展列////////////////////////////////////////////////////
                        string strsql2 = "select pt_id,pt_name from plot where pt_re_id=" + this.rbtrole.SelectedValue.ToString().Trim();
                        DataTable dtt = DbHelperSQL.dataTable(strsql2);
                        DataRow drr;
                        int dttsum = dtt.Rows.Count;
                        if (dttsum > 0)
                        {
                            for (int i = 0; i < dttsum; i++)
                            {
                                drr = dtt.Rows[i];                           
                                BoundColumn bcl = new BoundColumn();
                                bcl.DataField = "pe" + drr["pt_id"].ToString().Trim();
                                bcl.HeaderText = drr["pt_name"].ToString().Trim();
                                this.DataGrid1.Columns.AddAt(7 + i, bcl);
                            }
                        }

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