ASP.NET 2.0 中實現 Treeview 與資料庫的綁定(含代碼)

asp.net|treeview|資料|資料庫 編程思想：   每條記錄代表一個節點。通過表裡的 2 個數字型的核心欄位 f_NodeId、f_ParentNodeId 形成邏輯上的層次型關係。約定 0 代表根節點。其他欄位為輔助欄位，與本文關係不大。定義和初始化一對象數組 myNodes，然後一次性讀取表中的記錄，通過判斷當前節點的父節點，依次建立所有的上下級關係。樣本資料：運行結果：樣本下載：http://www.why100000.com/_ftps/samples/Tree+db.rar（代碼調試環境：Visual Web Developer 2005 Express Edition）Access資料庫名：db_system.mdb表名：tabItems表結構：    f_i_autoid      自動編號    f_NodeId        數字（本節點ID）    f_ParentNodeId  數字（父節點ID）    f_Name          文本    f_Tag           文本    f_Url           文本    f_order         數字    f_isHidden      文本    f_datetime      日期/時間

  關鍵代碼：using System;using System.Data;using System.Data.OleDb;using System.Configuration;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;

  public partial class _Default : System.Web.UI.Page{    protected void Page_Load(object sender, EventArgs e)    {        if (!IsPostBack)        {            string sDbPath = "./db_system.mdb";  //"            string sPassword = "";            string sDbTable = "tabItems";            OleDbConnection oConn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath(sDbPath) + ";Password=" + sPassword + ";");            OleDbDataReader oDr;

              try            {                oConn.Open();                OleDbCommand oCmd = new OleDbCommand("select * from " + sDbTable, oConn);  // + " order by f_level"                oDr = oCmd.ExecuteReader();

                  //定義對象數組                TreeNode[] myNodes = new TreeNode[100];

                  //初始化對象數組                for (int i = 0; i < myNodes.Length; i++)                {                    myNodes[i] = new TreeNode();                }

                  //從表中取資料                while (oDr.Read())                {                    int iParentNodeId = (int)oDr["f_ParentNodeId"];                    int iMyNodeId = (int)oDr["f_NodeId"];

                      if (iParentNodeId != 0)                    {                        myNodes[iMyNodeId].Text = oDr["f_name"].ToString();                        myNodes[iMyNodeId].NavigateUrl = oDr["f_url"].ToString();                        myNodes[iParentNodeId].ChildNodes.Add(myNodes[iMyNodeId]);                    }                    else                    {                        myNodes[iMyNodeId].Text = oDr["f_name"].ToString();                        myNodes[iMyNodeId].SelectAction = TreeNodeSelectAction.None;                        TreeView1.Nodes.Add(myNodes[iMyNodeId]);                    }                }            }

              catch (System.Exception sqle)            {                sqle.ToString().Replace("\n", "<br>");                Response.Write(sqle);            }            finally            {                oConn.Close();            }

          }

      }}