您可以在这里快速查找：


 
您的位置： 编程学习 > asp.net教程 > 200508
文章分类

Java技术
2005: 03 04 05 06 07 08
09 10 11 12
2006: 01 02

Asp.net
2005: 07 08 09 10 11 12
2006: 01 02

VB编程
2006: 02

Asp编程
2005: 11 12
2006: 01 02

C++/VC
2005: 10 11 12
2006: 01 02

Delphi
2005: 12
2006: 01 02

其它

 本文章适合所有读者

.NET平台下Web树形结构程序设计

lihonggen0

.NET平台下Web树形结构程序设计

    我的上篇文章《树形结构在开发中的应用》主要是在Windows Form下的实现，下面是Web Form下的实现。

数据库设计

首先，我们在SQL SERVER 2000里建立一个表tbTree，表的结构设计如下：

列名
数据类型
描述
长度
主键
ID
Int
节点编号
4
是
ParentID
Int
父节点编号
4
 
ConText
Nvarchar
我们要显示的节点内容
50
 

在SQL SERVER 2000中建表的脚本：

CREATE TABLE [dbo].[tbTree] (

       [ID] [int] IDENTITY (1, 1) NOT NULL ,

       [Context] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,

       [ParentID] [int] NULL

) ON [PRIMARY]

 
在表中添加如下记录：

SET IDENTITY_INSERT tbtree ON

insert tbtree (ID,Context,ParentID)  values ( 1,´中国´,0)

insert tbtree (ID,Context,ParentID)  values ( 2,´北京´,1)

insert tbtree (ID,Context,ParentID)  values ( 3,´天津´,1)

insert tbtree (ID,Context,ParentID)  values ( 4,´河北省´,1)

insert tbtree (ID,Context,ParentID)  values ( 5,´广东省´,1)

insert tbtree (ID,Context,ParentID)  values ( 6,´广州´,5)

insert tbtree (ID,Context,ParentID)  values ( 7,´四川省´,1)

insert tbtree (ID,Context,ParentID)  values ( 8,´成都´,7)

insert tbtree (ID,Context,ParentID)  values ( 9,´深圳´,5)

insert tbtree (ID,Context,ParentID)  values ( 10,´石家庄´,4)

insert tbtree (ID,Context,ParentID)  values ( 11,´辽宁省´,1)

insert tbtree (ID,Context,ParentID)  values ( 12,´大连´,11)

insert tbtree (ID,Context,ParentID)  values ( 13,´上海´,1)

insert tbtree (ID,Context,ParentID)  values ( 14,´天河软件园´,6)

insert tbtree (ID,Context,ParentID)  values ( 15,´汕头´,5)

SET IDENTITY_INSERT tbtree off

下载Treeview控件地址
http://msdn.microsoft.com/downloads/samples/internet/ASP_DOT_NET_ServerControls/WebControls/default.asp
安装后，通过“自定义工具箱”->“.net框架组件”把TreeView添加到工具箱里。
新建一个项目，选择Visual Basic.Net 工程Asp.net Web应用程序，在页面上拖画一个TreeView控件。
 
 
Html页：

<%@ Register TagPrefix="iewc" Namespace="Microsoft.Web.UI.WebControls" Assembly="Microsoft.Web.UI.WebControls, Version=1.0.2.226, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>

<%@ Page Language="vb" AutoEventWireup="false" Codebehind="WebForm1.aspx.vb" Inherits="Tree.WebForm1"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

<HTML>

     <HEAD>

         <title>WebForm1</title>

         <meta name="GENERATOR" content="Microsoft Visual Studio .NET 7.0">

         <meta name="CODE_LANGUAGE" content="Visual Basic 7.0">

         <meta name="vs_defaultClientScript" content="JavaScript">

         <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">

     </HEAD>

     <body MS_POSITIONING="GridLayout">

         <form id="Form1" method="post" runat="server">

              <FONT face="宋体">

                   <iewc:TreeView id="TreeView1" style="Z-INDEX: 101; LEFT: 39px; TOP: 68px" runat="server"></iewc:TreeView></FONT>

         </form>

     </body>

</HTML>

 
 
后台代码：

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Dim ds As New DataSet()

        Dim CN As New SqlConnection()

        Try

            ´初始化连接字符串

            CN.ConnectionString = "data source=pmserver;initial catalog=Benchmark;persist security info=False;user id=sa;Password=sa;"

            CN.Open()

            Dim adp As SqlDataAdapter = New SqlDataAdapter("select * from tbTree", CN)

            adp.Fill(ds)

            Me.ViewState("ds") = ds

        Catch ex As Exception

#If DEBUG Then

            Session("Error") = ex.ToString()

            Response.Redirect("error.aspx")        ´̀跳转程序的公共错误处理页面

#End If

        Finally

            ´关闭连接

            CN.Close()

        End Try

        ´调用递归函数，完成树形结构的生成

        AddTree(0, Nothing)

    End Sub

 

    ´递归添加树的节点

    Private Sub AddTree(ByVal ParentID As Integer, ByVal pNode As TreeNode)

        Dim ds As DataSet

        ds = Me.ViewState("ds")

        Dim dvTree As New DataView()

        dvTree = New DataView(ds.Tables(0))

        ´过滤ParentID,得到当前的所有子节点

        dvTree.RowFilter = "PARENTID = " + ParentID.ToString

 

        Dim Row As DataRowView

        For Each Row In dvTree

            Dim Node As New TreeNode()

            If pNode Is Nothing Then  ´判断是否根节点

                ´添加根节点

                Node.Text = Row("ConText").ToString()

                TreeView1.Nodes.Add(Node)

                Node.Expanded = True

                ´再次递归

                AddTree(Int32.Parse(Row("ID").ToString()), Node)

            Else

                ´̀添加当前节点的子节点

                Node.Text = Row("ConText").ToString()

                pNode.Nodes.Add(Node)

                Node.Expanded = True

                ´再次递归

                AddTree(Int32.Parse(Row("ID").ToString()), Node)

            End If

        Next

    End Sub

 
C#版本：
 
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 Microsoft.Web.UI.WebControls;
using System.Data.SqlClient;
namespace TreeCS
{
       /// <summary>
       /// WebForm1 的摘要说明
       /// </summary>
       public class WebForm1 : System.Web.UI.Page
       {
              protected Microsoft.Web.UI.WebControls.TreeView TreeView1;
      
              private void Page_Load(object sender, System.EventArgs e)
              {
                     // 定义数据库连接
                     SqlConnection CN = new SqlConnection();
                     try
                     {
                            //初始化连接字符串
                            CN.ConnectionString= "data source=pmserver;initial catalog=Benchmark;persist security info=False;user id=sa;Password=sa;";
                            CN.Open();
 
                            SqlDataAdapter adp = new SqlDataAdapter("select * from tbTree",CN);
                            DataSet ds=new DataSet();
                            adp.Fill(ds);
                            this.ViewState["ds"]=ds;
                     }
                     catch (Exception ex)
                     {
                            Session["Error"] = ex.ToString();
                            Response.Redirect("error.aspx");       //̀跳转程序的公共错误处理页面
                     }
                     finally
                     {
                            CN.Close();
                     }
                     //调用递归函数，完成树形结构的生成
                     AddTree(0, (TreeNode)null);
              }
 
              //递归添加树的节点
              public void AddTree(int ParentID,TreeNode pNode)
              {
                     DataSet ds=(DataSet) this.ViewState["ds"];
                     DataView dvTree = new DataView(ds.Tables[0]);
                     //过滤ParentID,得到当前的所有子节点
                     dvTree.RowFilter =  "[PARENTID] = " + ParentID;
 
                     foreach(DataRowView Row in dvTree)
                     {
                            TreeNode Node=new TreeNode() ;
                            if(pNode == null)
                            {    //添加根节点
                                   Node.Text = Row["ConText"].ToString();
                                   TreeView1.Nodes.Add(Node);
                                   Node.Expanded=true;
                                   AddTree(Int32.Parse(Row["ID"].ToString()), Node);    //再次递归
                            }
                            else
                            {   //̀添加当前节点的子节点
                                   Node.Text = Row["ConText"].ToString();
                                   pNode.Nodes.Add(Node);
                                   Node.Expanded = true;
                                   AddTree(Int32.Parse(Row["ID"].ToString()),Node);     //再次递归
                            }
                     }                  
              }           
 
              #region Web Form Designer generated code
              override protected void OnInit(EventArgs e)
              {
                     //
                     // CODEGEN该调用是 ASP.NET Web 窗体设计器所必需的。
                     //
                     InitializeComponent();
                     base.OnInit(e);
              }
             
              /// <summary>
              ///设计器支持所需的方法 - 不要使用代码编辑器修改
              /// 此方法的内容
              /// </summary>
              private void InitializeComponent()
              {   
                     this.Load += new System.EventHandler(this.Page_Load);
 
              }
              #endregion
       }
}
 
后记：请读者自行修改程序中的连接字符串设置。
 
声明：本文版权与解释权归李洪根所有，如需转载，请保留完整的内容及此声明。
QQ: 21177563  
MSN: lihonggen@hotmail.com
专栏：http://www.csdn.net/develop/author/netauthor/lihonggen0/