C# winform combobox 在绑定数据之后插入一项选择项

 1        /**//// <summary>
 2        /// 填充comboboxB超医师 geovindu@163.com 涂聚文
 3        ///2009-02-16
 4        /// </summary>
 5        private void setDBPyhNameComboBox()
 6        {
 7
 8            this.combPhy.DataSource = null;
 9
            DBConnectioin dbc = new DBConnectioin();
            SqlConnection conn = new SqlConnection(DBConnectioin.conStr);
            conn.Open();
            //DbHelperSQL.setComboList(combPhy, "select PhyID,PhyName  from Physician", "Physician", "PhyName", "PhyID");
            string sSQL = "select PhyID,PhyName  from Physician";
            string sTable = "Physician";

 
            DataSet dsCourtesy = new DataSet();
            SqlDataAdapter daCourtesy = new SqlDataAdapter();
            DbHelperSQL.setCommand(dsCourtesy, daCourtesy, sSQL, sTable);
            daCourtesy.Fill(dsCourtesy);
            combPhy.DataSource = dsCourtesy.Tables[0].DefaultView;              
            DataRow dr = dsCourtesy.Tables[0].NewRow();
            combPhy.DisplayMember = "PhyName";
            combPhy.ValueMember = "PhyID";            
            dr["PhyName"] = "全部";  
            dr["PhyID"] = -1;  
            dsCourtesy.Tables[0].Rows.InsertAt(dr, 0);
            //combPhy.Text = "全部";


        }

 ProductCatalogListBLL productCatalogListBLL = new ProductCatalogListBLL();
        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                BindClass();
            }
        }
        /// <summary>
        /// 
        /// </summary>
        void BindClass()
        {
            List<ProductCatalogListInfo> list = productCatalogListBLL.get_List();
            foreach (ProductCatalogListInfo model in list)
            {
                ListItem li = new ListItem();
                li.Text = "╋" + model.ProductCatalogName;
                li.Value = model.ProductCatalogId.ToString();
                DropDownList1.Items.Add(li);
                BindChild(model.ProductCatalogId.ToString(), "├──");
            }
        }
        /// <summary>
        /// 
        /// </summary>
        /// <param name="ParentID"></param>
        /// <param name="separator"></param>
        void BindChild(string ParentID, string separator)
        {
            List<ProductCatalogListInfo> list = productCatalogListBLL.get_List(ParentID);
            foreach (ProductCatalogListInfo model in list)
            {
                ListItem li = new ListItem();
                li.Text = separator + model.ProductCatalogName;
                li.Value = model.ProductCatalogId.ToString();
                DropDownList1.Items.Add(li);
                string separator_ = separator + "───";
                BindChild(model.ProductCatalogId.ToString(), separator_);
            }
        }

　　

 /// <summary>
        /// 
        /// </summary>
        /// <returns></returns>
        public List<ProductCatalogListInfo> get_List()
        {
            List<ProductCatalogListInfo> List = new List<ProductCatalogListInfo>();
            DataTable dt = DBHelper.getDataSet("select * from ProductCatalogList where ProductCatalogParent=0 order by ProductCatalogId desc").Tables[0];
            foreach (DataRow dr in dt.Rows)
            {
                ProductCatalogListInfo model = new ProductCatalogListInfo();
                model.ProductCatalogId = Convert.ToInt32(dr["ProductCatalogId"]);
                model.ProductCatalogName = dr["ProductCatalogName"].ToString();
                model.ProductCatalogParent = Convert.ToInt32(dr["ProductCatalogParent"]);
                List.Add(model);
            }
            return List;
        }
        /// <summary>
        /// 
        /// </summary>
        /// <param name="ParentID"></param>
        /// <returns></returns>
        public List<ProductCatalogListInfo> get_List(string ParentID)
        {
            List<ProductCatalogListInfo> List = new List<ProductCatalogListInfo>();
            DataTable dt = DBHelper.getDataSet("select * from ProductCatalogList where ProductCatalogParent=" + ParentID + " order by ProductCatalogId desc").Tables[0];
            foreach (DataRow dr in dt.Rows)
            {
                ProductCatalogListInfo model = new ProductCatalogListInfo();
                model.ProductCatalogId = Convert.ToInt32(dr["ProductCatalogId"]);
                model.ProductCatalogName = dr["ProductCatalogName"].ToString();
                model.ProductCatalogParent = Convert.ToInt32(dr["ProductCatalogParent"]);
                List.Add(model);
            }
            return List;
        }