Treeview Node Related data

In this blog we will know when we click node records its related data will be displayed in datagridview.

App.config

 <?xml version="1.0" encoding="utf-8" ?>
<configuration>
<
appSettings>
            <
add key="dsn" value="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=..\EMP.mdb" />
      </appSettings>
</
configuration

Form1.cs

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.OleDb;
namespace Treeview_Node__Related_data
{
    public partial class Form1 : Form
    {
        string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"];
        OleDbCommand com;
        OleDbDataAdapter oledbda;
        DataSet ds;
        string str;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            treeView1.Nodes.Add("Please select any Name");
            OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select * from student";
            com = new OleDbCommand(str, con);
            OleDbDataReader reader = com.ExecuteReader();
            while (reader.Read())
            {
                treeView1.Nodes.Add(reader["sname"].ToString());
            }
            reader.Close();
            con.Close(); 
        }

        private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
        {
            OleDbConnection con = new OleDbConnection(ConnectionString);
                con.Open();
                str = "select * from student where sname='" + treeView1.SelectedNode.Text + "'";
                com = new OleDbCommand(str, con);
                oledbda = new OleDbDataAdapter(com);
                ds = new DataSet();
                oledbda.Fill(ds, "student");
                dataGridView1.DataMember = "student";
                dataGridView1.DataSource = ds;
                con.Close();
        }
    }
}