รบกวนช่วยดูให้หน่อยค่ะ datagridviewcomboBoxColumn ทุกครั้งที่คลิก ปุ่ม submit มันจะเบิ้ลเพิ่มขึ้นเรื่อยๆ ค่ะ

private void ShowGrid() {
            string year = DateTime.Now.ToString("yyyy", new System.Globalization.CultureInfo("en-US"));
            DalBillTruck d = new DalBillTruck();
            string sql_db = "SELECT KEBillTruck.DocDate, KEBillTruck.DocNo, KEBillTruck.CarCode, KEBillTruck.CarCodeSub, KECustomer.Name1 AS CustName, " ;
            sql_db += " KEItem.Name1 AS ItemName,KEBillTruck.CreateCode, KEBillTruck.CreateDateTime, KEBillTruck.LastEditorCode, KEBillTruck.LastEditDateT, ";
                sql_db +=" KEBillTruck.IsRefund, KEBillTruck.TripType,KEBillTruck.WayCode, KEBillTruck.KM, KEBillTruck.RateUp, KEBillTruck.RateDown, " ;
                sql_db +=" KEItem.GroupCode FROM KEBillTruck INNER JOIN KEItem ON KEBillTruck.ItemCode = KEItem.Code INNER JOIN " ;
                sql_db +=" KECustomer ON KEBillTruck.CustCode = KECustomer.Code " ;
                sql_db += " WHERE (KEBillTruck.DocDate >= '" + DateConvert.DateNoTime(dateF.Value) + "' AND KEBillTruck.DocDate <= '" + DateConvert.DateNoTime(dateT.Value) + "' )";
                sql_db += " AND (KEItem.Code = 'p44081' OR KEItem.Code = 'J44070' OR KEItem.Code = 'F44064' OR KEItem.Code = 'F44066') ";
                if (txtSearchDocNo.TextLength != 0) { sql_db += " AND (KEBillTruck.DocNo like '%" + txtSearchDocNo.Text + "%' OR KEItem.Name1 like '%" + txtSearchDocNo.Text + "%') "; }
                if (txtSearchCust.TextLength != 0) { sql_db += " AND (KECustomer.Name1 like '%" + txtSearchCust.Text + "%' OR KEBillTruck.CarCode like '%" + txtSearchCust.Text + "%') "; }
                sql_db += " order by KEBillTruck.DocNo Desc";
            try {
                d.OpenbySql(sql_db);
                dv = new DataView(d.DataTable);

            } catch (Exception ex) {
                Msg.MsgError(ex.Message);
                return;
            }
            DataGridView1.DataSource = dv;// d.DataTable;
            setHeadCol();
                foreach (DataGridViewRow row in DataGridView1.Rows)
                {
                   DataGridViewComboBoxCell cbCell = (DataGridViewComboBoxCell)row.Cells[11];
                   cbCell.Value = row.Cells["TripType"].Value;
                    if (row.Cells["TripType"].Value.ToString() == "-1" || row.Cells["TripType"].Value.ToString() == null)
                    {
                        row.Cells["colType"].Value = 0;
                    }

                }
            
            lblCount.Text = "รวมรายการ : " + d.Count;
        }


int intCol = 0;
        DataGridViewComboBoxColumn colType;
        private void DataGridView1_DataBindingComplete(object sender, DataGridViewBindingCompleteEventArgs e)
        {
            DataGridView1.Columns["TripType"].Visible = false;
            DalBillTruck dd = new DalBillTruck();
            string sql = "SELECT tranID, tran_name FROM KETran";
            try
            {
                dd.OpenbySql(sql);
                dv2 = new DataView(dd.DataTable);

            }
            catch (Exception ex)
            {
                Msg.MsgError(ex.Message);
                return;
            }
            BindingSource BindSource = new BindingSource();
            BindSource.DataSource = dv2;
            if (intCol == 0)
            {
                if (DataGridView1.Rows.Count != 0)
                {
                    colType = new DataGridViewComboBoxColumn();
                    colType.HeaderText = "colType";
                    colType.DataSource = BindSource;
                    colType.ValueMember = "tranID";
                    colType.DisplayMember = "tran_name";
                    colType.Width = 100;
                    colType.Name = "colType";
                    colType.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleCenter;
                    DataGridView1.Columns.Insert(11,colType);

                }
                //intCol++;
            }
        }