0
Answer

TreeView with BackGroundWorker

Hi Experts,

I am trying to Populate the treeview with the backgroundworker control but did not get the parent and child nodes in
expected hierarchy.. 

My coding:

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.Configuration;
using System.Data.SqlClient;

namespace TvBackGroundWorker
{
    public partial class Form1 : Form
    {
        SqlConnection conn;
         TreeNode parentNode = null; 
         TreeNode childNode; 
        DataTable dt = new DataTable();
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            String connectionString;
            connectionString = ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;
            conn = new SqlConnection(connectionString);
            String Sequel = "SELECT MAINMNU,MENUPARVAL,STATUS FROM MNUPARENT ORDER BY 2";
            SqlDataAdapter da = new SqlDataAdapter(Sequel, conn); 
            conn.Open();
            da.Fill(dt);

            backgroundWorker1.RunWorkerAsync();
        }

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            foreach (DataRow dr in dt.Rows)
            {
                parentNode = (TreeNode)treeView1.Invoke(new Add(Add1), new object[] { dr["MAINMNU"].ToString()});
                PopulateTreeView(Convert.ToInt32(dr["MENUPARVAL"].ToString()), parentNode); 
            } 
        }

        private void PopulateTreeView(int parentId, TreeNode parentNode)
        {
            String Seqchildc = "SELECT MENUPARVAL,FRM_CODE,FRM_NAME,MNUSUBMENU FROM MNUSUBMENU WHERE MENUPARVAL=" + parentId + "";
            SqlDataAdapter dachildmnuc = new SqlDataAdapter(Seqchildc, conn);
            DataTable dtchildc = new DataTable();
            dachildmnuc.Fill(dtchildc);

            foreach (DataRow dr in dtchildc.Rows)
            {
                if (parentNode == null)
                {  //childNode = treeView1.Nodes.Add(dr["FRM_NAME"].ToString()); 
                    childNode = (TreeNode)treeView1.Invoke(new Add(Add2), new object[] { dr["FRM_NAME"].ToString() });
                    
                }
                else
                {
                    //childNode = parentNode.Nodes.Add(dr["FRM_NAME"].ToString());
                    childNode = (TreeNode)treeView1.Invoke(new Add(Add2), new object[] { dr["FRM_NAME"].ToString() });
                    System.Threading.Thread.Sleep(1000);
                }
                PopulateTreeView(Convert.ToInt32(dr["MNUSUBMENU"].ToString()), childNode);
            }
 
        }

        public delegate TreeNode Add(string txt);

        public TreeNode Add1(string txt)
        {
            parentNode = treeView1.Nodes.Add(txt);
            return parentNode;
        }


        public TreeNode Add2(string txt)
        {
            if(parentNode == null)
                childNode = treeView1.Nodes.Add(txt);
            else
                childNode = parentNode.Nodes.Add(txt);
            return childNode;
            
        }

    }
}

Tables Used

For Root or Parent Nodes

CREATE TABLE [dbo].[MNUPARENT](
[MAINMNU] [varchar](20) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
[STATUS] [varchar](1) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
[MENUPARVAL] [int] IDENTITY(1,1) NOT NULL,
 CONSTRAINT [PK_MNUPARENT] PRIMARY KEY CLUSTERED 
(
[MENUPARVAL] ASC
)WITH (PAD_INDEX  = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]

Child Nodes


CREATE TABLE [dbo].[MNUSUBMENU](
[MENUPARVAL] [int] NOT NULL,
[FRM_CODE] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
[FRM_NAME] [varchar](20) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[MNUSUBMENU] [int] NOT NULL,
[STATUS] [varchar](1) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
PRIMARY KEY CLUSTERED 
(
[MNUSUBMENU] ASC
)WITH (PAD_INDEX  = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]


Sample Insert in MNUPARENT Table

INSERT INTO MNUPARENT(MAINMNU, STATUS, MENUPARVAL) VALUES('Finanace','Y',1)

INSERT INTO MNUPARENT(MAINMNU, STATUS, MENUPARVAL) VALUES('Inventory','Y',2)

Sample Insert in MNUSUBMENU Table




INSERT INTO MNUSUBMENU(MENUPARVAL,FRM_NAME,MNUSUBMENU,STATUS) VALUES(1,'Child Finance',10,'Y')

INSERT INTO MNUSUBMENU(MENUPARVAL,FRM_NAME,MNUSUBMENU,STATUS) VALUES(1,'Accounting',20,'Y')

INSERT INTO MNUSUBMENU(MENUPARVAL,FRM_NAME,MNUSUBMENU,STATUS) VALUES(20,'Audit',30,'Y')

INSERT INTO MNUSUBMENU(MENUPARVAL,FRM_NAME,MNUSUBMENU,STATUS) VALUES(30,'Acc. Standards',40,'Y')



Any help appreciated.

Thanks Shankar