HYPDM.WinUI.ProductsAndParts.Parts.PartsStructAddForm.selectProduct C# (CSharp) Method

        private void selectProduct()
        {
            string t_productId = null;
            string t_productNo = "";//产品编号
            for (int i = 0; i < this.dgv_productList.Rows.Count; i++)
            {
                DataGridViewCheckBoxCell checkcell = (DataGridViewCheckBoxCell)dgv_productList.Rows[i].Cells[0];
                Boolean flag = Convert.ToBoolean(checkcell.Value);
                if (flag)
                {
                    t_productId = dgv_productList.Rows[i].Cells["PRODUCTID"].Value.ToString().Trim();
                    t_productNo = dgv_productList.Rows[i].Cells["PRODUCTNO"].Value.ToString().Trim();
                }
            }
            if (t_productId == null) { MessageBox.Show("请选择一个产品"); return; }

            if (this.copy_Product.PRODUCTID == t_productId)
            {
                MessageBox.Show("产品不能与自己关联"); return;
            }

            if (filterSelect(t_productId)==-1)
            {
                MessageBox.Show("该产品已经在产品结构中"); return;
            }

            if (filterCycle(t_productId))
            {
                MessageBox.Show(t_productNo+"结构中包含:"+this.copy_Product.PRODUCTNO+",不能添加。\n否则产品结构形成循环！"); return;
            }

            HYPDM.Entities.PDM_STRUCT temp_struct = new HYPDM.Entities.PDM_STRUCT();
            temp_struct.OBJECTID = this.copy_Product.PRODUCTID;
            temp_struct.ASSOBJECTID = t_productId;

            StructAddForm o = new StructAddForm(temp_struct, m_assoID, this.m_assoType);
            o.StartPosition = FormStartPosition.CenterParent;
            o.ShowDialog();
        }