利用ASP.NET的menu和SQL数据库制作无限级别菜单

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using WebTools;
public partial class Default4 : System.Web.UI.Page
{
    public int parentID;
    public Tools Connectionstr1 = new Tools();
    protected void Page_Load(object sender, EventArgs e)
    {
        string Connectionstr = Connectionstr1.connStr.ConnectionString;
         SqlConnection SconnStr = new SqlConnection(Connectionstr);
        //设定数据库操作命令
         SconnStr.Open();
         SqlCommand Scmd = new SqlCommand("select * from menuTable where parentID=0", SconnStr);
         SqlDataReader odr = Scmd.ExecuteReader();
        while (odr.Read())
        {
             MenuItem menuNode = new MenuItem();
             menuNode.Text = odr["menuName"].ToString();
             menuNode.Value = odr["id"].ToString();
             menuNode.Enabled = true;
             menuNode.Target = odr["target"].ToString();
             menuNode.NavigateUrl = odr["url"].ToString();
             Menu1.Items.Add(menuNode);
             parentID = Convert.ToInt16(odr["id"].ToString());
             addchildmenu1(menuNode, menuNode.Value);
         }
        //关闭数据库连接
         Scmd.Connection.Close();
     }
    protected void addchildmenu1(MenuItem pnode,string pid)
    {
        string Connectionstr = Connectionstr1.connStr.ConnectionString;
         SqlConnection SconnStr1 = new SqlConnection(Connectionstr);
        //设定数据库操作命令
         SconnStr1.Open();
         SqlCommand Scmd1 = new SqlCommand("select * from menuTable where parentID=" + parentID + "", SconnStr1);
         SqlDataReader odr = Scmd1.ExecuteReader();
        while (odr.Read())
        {
             MenuItem menuNode = new MenuItem();
             menuNode.Text = odr["menuName"].ToString();
             menuNode.Value = odr["id"].ToString();
             menuNode.Enabled = true;
             menuNode.Target = odr["target"].ToString();
             menuNode.NavigateUrl = odr["url"].ToString();
             pnode.ChildItems.Add(menuNode);
             parentID = Convert.ToInt16(odr["id"].ToString());
             addchildmenu2(menuNode, menuNode.Value);
         }
        //关闭数据库连接
         Scmd1.Connection.Close();
     }
    protected void addchildmenu2(MenuItem pnode, string pid)
    {
        string Connectionstr = Connectionstr1.connStr.ConnectionString;
         SqlConnection SconnStr1 = new SqlConnection(Connectionstr);
        //设定数据库操作命令
         SconnStr1.Open();
         SqlCommand Scmd1 = new SqlCommand("select * from menuTable where parentID=" + parentID + "", SconnStr1);
         SqlDataReader odr = Scmd1.ExecuteReader();
        while (odr.Read())
        {
             MenuItem menuNode = new MenuItem();
             menuNode.Text = odr["menuName"].ToString();
             menuNode.Value = odr["id"].ToString();
             menuNode.Enabled = true;
             menuNode.Target = odr["target"].ToString();
             menuNode.NavigateUrl = odr["url"].ToString();
             pnode.ChildItems.Add(menuNode);
             parentID = Convert.ToInt16(odr["id"].ToString());
             addchildmenu1(menuNode, menuNode.Value);
         }
        //关闭数据库连接
         Scmd1.Connection.Close();
     }
}