TreeView加載省市數據

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.Xml;

namespace 省市縣加載到TreeView
{
    public partial class AreaFrm : Form
    {
        public AreaFrm()
        {
            InitializeComponent();
        }

        private void AreaFrm_Load(object sender, EventArgs e)
        {

        }

        private void btnLoadData_Click(object sender, EventArgs e)
        {
            int pid = 0;

            //1.讀取TblArea中的數據
            LoadAreaInfo(pid, treeViewArea.Nodes);
        }

        /// <summary>
        /// 加載TblArea中的數據
        /// </summary>
        /// <param name="pid"></param>
        /// <param name="treeNodeCollection"></param>
        private void LoadAreaInfo(int pid, TreeNodeCollection treeNodeCollection)
        {

            //1.先執行查詢,查詢所有TblArea等於pid的
            string sql = "select * from TblArea where AreaPid =@AreaPid";
            SqlParameter ps = new SqlParameter("@AreaPid", pid);
            DataTable dt = SqlHelper.SqlHelper.ExecuteTable(sql, CommandType.Text, ps);

            //2.將dt中的數據綁定到TreeNodeCollection上
            foreach (DataRow item in dt.Rows)
            {
                TreeNode tNode = treeNodeCollection.Add(item[1].ToString());
                tNode.Tag = item[0];
                //3.讀取某省下面的所有城市，然後將這些數據加載到省節點上

                LoadAreaInfo((int)item[0], tNode.Nodes);
            }

        }    
    }
}

源代碼和數據庫下載：
http://download.csdn.net/detail/gongchao1212/9080183