Master detail view : DataBinding ListBox « GUI Windows Forms « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. GUI Windows Forms
3. DataBinding ListBox

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;

  public class MasterDetail : System.Windows.Forms.Form
  {
    public MasterDetail()
    {
      this.lstCategories = new System.Windows.Forms.ListBox();
      this.lstProducts = new System.Windows.Forms.ListBox();
      this.label1 = new System.Windows.Forms.Label();
      this.label2 = new System.Windows.Forms.Label();
      this.SuspendLayout();
      // 
      this.lstCategories.Location = new System.Drawing.Point(8, 28);
      this.lstCategories.Size = new System.Drawing.Size(140, 225);
      this.lstCategories.TabIndex = 0;
      this.lstCategories.SelectedIndexChanged += new System.EventHandler(this.lstCategories_SelectedIndexChanged);
      // 
      this.lstProducts.Location = new System.Drawing.Point(152, 28);
      this.lstProducts.Size = new System.Drawing.Size(252, 225);
      this.lstProducts.TabIndex = 1;
      // 
      this.label1.Location = new System.Drawing.Point(8, 8);
      this.label1.Size = new System.Drawing.Size(108, 16);
      this.label1.TabIndex = 2;
      this.label1.Text = "Category:";
      // 
      this.label2.Location = new System.Drawing.Point(152, 8);
      this.label2.Size = new System.Drawing.Size(108, 16);
      this.label2.TabIndex = 3;
      this.label2.Text = "Products:";
      // 
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 14);
      this.ClientSize = new System.Drawing.Size(412, 266);
      this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                      this.label2,
                                      this.label1,
                                      this.lstProducts,
                                      this.lstCategories});
      this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
      this.Text = "A Master-Detail Form";
      this.Load += new System.EventHandler(this.MasterDetail_Load);
      this.ResumeLayout(false);

    }

    string connectionString = "Data Source=localhost;Initial Catalog=Northwind;Integrated Security=SSPI";
    string categorySQL = "SELECT * FROM Categories";
    string productSQL = "SELECT * FROM Products";

    DataSet ds = new DataSet();
    DataRelation relation;

    private System.Windows.Forms.ListBox lstCategories;
    private System.Windows.Forms.Label label1;
    private System.Windows.Forms.Label label2;
    private System.Windows.Forms.ListBox lstProducts;

    public static void Main()
    {
      Application.Run(new MasterDetail());
    }

    private void MasterDetail_Load(object sender, System.EventArgs e)
    {
      SqlConnection con = new SqlConnection(connectionString);
      SqlCommand com = new SqlCommand(categorySQL, con);
      SqlDataAdapter adapter = new SqlDataAdapter(com);
    
        con.Open();
      adapter.Fill(ds, "Categories");
      adapter.SelectCommand.CommandText = productSQL;
      adapter.Fill(ds, "Products");
      con.Close();

      DataColumn parentCol = ds.Tables["Categories"].Columns["CategoryID"];
      DataColumn childCol = ds.Tables["Products"].Columns["CategoryID"];
      relation = new DataRelation("Cat_Prod", parentCol, childCol);
      ds.Relations.Add(relation);

      foreach (DataRow row in ds.Tables["Categories"].Rows)
      {
        lstCategories.Items.Add(row["CategoryName"]);
      }
    }

    private void lstCategories_SelectedIndexChanged(object sender, System.EventArgs e)
    {
            lstProducts.Items.Clear();

      DataRow[] rows = ds.Tables["Categories"].Select("CategoryName='" + lstCategories.Text + "'");
      DataRow parent = rows[0];

      foreach (DataRow child in parent.GetChildRows(relation))
      {
        lstProducts.Items.Add(child["ProductName"]);
      }
    }
  }