treeview绑定数据库时发生错误.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;namespace tree
{
    
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void MyTreeView(DataTable table, string ParentID, System.Windows.Forms.TreeNode PNode)
        {
            
            DataRow[] dr = table.Select("ParentID=" + ParentID);
            try
            {
                if (dr.Length > 0)
                {
                    foreach (DataRow d in dr)
                    {                        System.Windows.Forms.TreeNode TNode = new System.Windows.Forms.TreeNode();   //创建TNode对像
                        TNode.Text = d["powerNAME"].ToString();                           //显示子点文本
                        if (PNode == null)
                        {
                            this.TreeView1.Nodes.Add(TNode);                             //添加父子点
                        }
                        else
                        {
                            PNode.Nodes.Add(TNode);                                   //添加子节点
                        }                        MyTreeView(table, d["powerID"].ToString(), TNode);                   //调用MyTreeView
                    }
                }
                else
                {
                    return;
                }
            }
            catch (Exception exp)
            {
                MessageBox.Show(exp.Message);                                       //提示错误信息
            }
        }    }
}
如上面代码所示,我在vs2005中编译时发生如下错误:
错误 1 “tree.Form1”并不包含“TreeView1”的定义 C:\Documents and Settings\gaojin\My Documents\Visual Studio 2005\Projects\tree\tree\Form1.cs 33 34 tree
请高手指点!