递归绑定TreeView

DataAccess.DT();是返回所有地区信息(返回类型DataTable)

        #region 控件递归算法
        private static DataTable dt = DataAccess.DT();
        /// <summary>
        /// TreeView递归算法
        /// </summary>
        /// <param name="f_id">父ID</param>
        /// <param name="tn">TreeView对象</param>
        public static void ControllerTestTree(string f_id, TreeNodeCollection tn)
        {
            foreach (DataRow item in dt.Rows)
            {
                if (item[3].ToString().Trim() == f_id)
                {
                    TreeNode _treenode = new TreeNode();
                    _treenode.Text = item[2].ToString().Trim();
                    _treenode.Value = item[1].ToString().Trim();
                    _treenode.Expanded = false;/*不展开节点*/
                    tn.Add(_treenode);
                    ControllerTestTree(item[1].ToString().Trim(), _treenode.ChildNodes);
                }
            }
        }
        #endregion

调用：

        //******************控件递归*******************//
        protected void Button2_Click(object sender, EventArgs e)
        {
            ControllerTestTree("0", this.TreeView1.Nodes);
            this.TreeView1.Nodes[0].Expanded = true;/*展开第一级目录(节点)*/
        }