TreeView动态绑定

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

public partial class Default2 : System.Web.UI.Page
{
    string conString = ConfigurationManager.ConnectionStrings["heihei"].ConnectionString;
    protected void Page_Load(object sender, EventArgs e)
    {
        DataTable dt = SelectAllFather();
        foreach(DataRow dr in dt.Rows)
        {
            string nodesid = dr[0].ToString();
            string displayname = dr[1].ToString();
            TreeNode fatherNode = this.CreatTreeNode(displayname, nodesid);
            CreateChildTree(nodesid, fatherNode);
            TreeView1.Nodes.Add(fatherNode);
        }

    }

    private void CreateChildTree(string nodesid, TreeNode fatherNode)
    {
        DataTable dt = SelectAllChildById(nodesid);
        foreach (DataRow dr in dt.Rows)
        {
            string cinodeid = dr[0].ToString();
            string cinodename = dr[1].ToString();
            TreeNode tnode = CreatTreeNode(cinodename, cinodeid);
            AddTree(fatherNode, tnode);
        }
    }

    private TreeNode CreatTreeNode(string displayname, string nodesid)
    {
        TreeNode newnode = new TreeNode();
        newnode.Text = displayname;
        newnode.Value = nodesid;
        return newnode;
    }

    private void AddTree(TreeNode fatherNode, TreeNode tnode)
    {
        fatherNode.ChildNodes.Add(tnode);
    }

    //选出所有的父类
    public DataTable SelectAllFather() {
        string sql = "select * from  tb_Father";
         DataTable dt = new DataTable();
        SqlConnection conn = new SqlConnection(conString);
        conn.Open();
        SqlCommand cmd = new SqlCommand(sql, conn);
        SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
        dt.Load(dr);
        return dt;
    }

    //根据id选出所有的子类
    public DataTable SelectAllChildById(string id)
    {
        string sql = "select * from tb_Son where father_Id =" + id + "";
        DataTable dt = new DataTable();
        SqlConnection conn = new SqlConnection(conString);
        conn.Open();
        SqlCommand cmd = new SqlCommand(sql, conn);
        SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
        dt.Load(dr);
        return dt;
    }
}