调试易

namespace wxfj
{
    class Public_Fun
    {
        #region[公共变量] 
        DataSet DS;
        DataTable DT;
        SQL_Link Link = new SQL_Link();
        bool Tree_Node_P = false;
        #endregion        #region[函数] [TreeView递归函数]         #region [函数] [树型2级显示]
        public void Fun_Tree(TreeView TREE,SqlConnection Link_Conn)
        {
            DS = Link.SQL_Select("select * from Basic_Bm", Link_Conn);
            DT = DS.Tables[0]; 
            if (Tree_Node_P == false)
            {
                foreach (DataRow DR in DT.Rows)
                {
                    if (DR.ItemArray[1].ToString() == "0")                     {
                        TreeNode TN = new TreeNode();
                        TN.Text = DR.ItemArray[0].ToString();
                        TREE.Nodes.Add(TN);
                    }                 }
                Tree_Node_P = true;
            }            foreach (DataRow DR_2 in DT.Rows)
            {
                foreach (TreeNode TN_2 in TREE.Nodes)                 {
                    if (DR_2.ItemArray[1].ToString() == TN_2.Text)
                    {
                        TreeNode TN_3 = new TreeNode();
                        TN_3.Text = DR_2.ItemArray[0].ToString();                         TN_2.Nodes.Add(TN_3);
                        Fun_Tree_2(TN_3);
                    }
                }
            }
        }
        #endregion        #region [函数] [树型>3级递归] 
        public void Fun_Tree_2(TreeNode T_Name)
        {
            foreach (DataRow DR_2 in DT.Rows)
            {
                if (DR_2.ItemArray[1].ToString() == T_Name.Text) 
                {
                    TreeNode TN_3 = new TreeNode();
                    TN_3.Text = DR_2.ItemArray[0].ToString();
                    T_Name.Nodes.Add(TN_3);
                    Fun_Tree_2(TN_3); 
                }
            }
        }
          }
}

用TreeView来做的：
    protected void BindTree()
    {
        TreeNode node = new TreeNode();   //这里是创建一个根节点,就是dome中看到的Root   
        node.Text = "Root";
        CreateChildTree(node, 0);
       TreeView1.Nodes.Add(node);
    }    protected void CreateChildTree(TreeNode _parentNode, int _parentID)
    {
        using (SqlConnection _conn = new SqlConnection(music.constr))
        {
            SqlCommand _comm = new SqlCommand();
            string sql = "select * from menu where rootid=@rootid";
            _comm.Parameters.Add("@rootid", SqlDbType.Int).Value = _parentID;
            _comm.CommandText = sql;
            _comm.Connection = _conn;
            _conn.Open();
            using (SqlDataReader r = _comm.ExecuteReader())
            {
                while (r.Read())
                {
                    TreeNode _node = new TreeNode(r["title"].ToString());
                    CreateChildTree(_node, (int)r["ID"]);  //递归出子节点   
                    _parentNode.ChildNodes.Add(_node);
                }
            }
        }
    }