using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

namespace WebApplication1
{
    /// <summary>
    /// WebForm5 的摘要说明。
    /// </summary>
    public class WebForm5 : System.Web.UI.Page
    {
        protected Microsoft.Web.UI.WebControls.TreeView TreeView1;
        Microsoft.Web.UI.WebControls.TreeNode rootnode;
      
    
        private void Page_Load(object sender, System.EventArgs e)
        {
            // 在此处放置用户代码以初始化页面
            SqlConnection con=new SqlConnection("server=GOODBABY;uid=sa;password=goodbaby;database=Northwind");
            DataSet myDS=new DataSet();
            SqlDataAdapter mySqlDAP=new SqlDataAdapter("select EmployeeID,ReportsTo,LastName from Employees",con);
            try
            {
                con.Open();
                mySqlDAP.Fill(myDS,"Employees");
                DataTable myDataTable=myDS.Tables["Employees"];
                myDS.Relations.Add("SelfReferencing",myDataTable.Columns["EmployeeID"],myDataTable.Columns["ReportsTo"],false);
                foreach(DataRow Item in myDataTable.Rows)
                {
                    if(Item.IsNull("ReportsTo"))
                    {
                        Microsoft.Web.UI.WebControls.TreeNode treenode=new Microsoft.Web.UI.WebControls.TreeNode();
                        treenode.Text=(string)Item["LastName"];
                        rootnode=treenode;
                        TreeView1.Nodes.Add(treenode);
                        ForTree(treenode,Item);
                        break;
                    }
                }
            }
            catch(Exception ex)
            {
                throw ex;
            }
        }


        private void ForTree( Microsoft.Web.UI.WebControls.TreeNode node,DataRow row)
        {
            if(!row.IsNull("ReportsTo"))
            {
                Microsoft.Web.UI.WebControls.TreeNode tempNode=new Microsoft.Web.UI.WebControls.TreeNode();
                tempNode.Text=(string)row["LastName"];
                node.Nodes.Add(tempNode);
                foreach(DataRow Item in row.GetChildRows("SelfReferencing"))
                {
                    ForTree(tempNode,Item);
                }
            }
            else
            {
                Microsoft.Web.UI.WebControls.TreeNode tempNode;
                tempNode=node;
                foreach(DataRow Item in row.GetChildRows("SelfReferencing"))
                {
                    ForTree(tempNode,Item);
                }
            }
            
        }

        Web 窗体设计器生成的代码
    }
}