How to create a simple Master-Slave DataGrid

Introduction

In this article, I will provide code sample on how to make a simple Master-Slave DataGrid. First, add a DataGrid on the page and make a "Select" column using property builder.

Master-Slave DataGrid in C# Code

private void Page_Load(object sender, System.EventArgs e)
{
  if(!Page.IsPostBack) 
  { 
    // Binds the DataGrid
    BindGrid(); 

    }
  } 
  public void BindGrid() 
  { 
    SqlCommand myCommand = 
        new SqlCommand("SELECT * FROM Categories",myConnection); 
    myCommand.CommandType = CommandType.Text; 
    try 
    { 
      // Opens database connection
      myConnection.Open(); 
      // Execute SqlCommand that returns datareader
      SqlDataReader dr = 
          myCommand.ExecuteReader(CommandBehavior.CloseConnection);
      // Populate MasterGrid
      MasterGrid.DataSource = dr; 
      // Binds MasterGrid to the page
      MasterGrid.DataBind(); 

    } 

    // Catch SqlException 
    catch ( SqlException SqlEx ) 
    { 
      // TODO
    }
    // Catch general Exception
    catch ( Exception ex ) 
    {
      // TODO
    }
    // Closes the database connection
    finally { myConnection.Close(); } 
  }

  // This event is fired when the Selection is made in MasterDataGrid
  private void ViewSelectionDetails(object sender, System.EventArgs e)
  {
    // Gets the primary key value from the Master DataGrid
    Int32 categoryID = 
         Convert.ToInt32(MasterGrid.SelectedItem.Cells[0].Text); 
    Label2.Text = categoryID.ToString();
    // Sends the key to the Slave DataGrid
    PopulateSlaveGrid( categoryID );

  }
  // This method populates Slave DataGrid
  public void PopulateSlaveGrid(Int32 cID) 
  { 
    // SQL QUERY to view the selected Item details
    string commandString = 
      "SELECT CategoryName,Description FROM Categories WHERE CategoryID="+cID; 

    // Make an instance of SqlDataAdapter and Assign it the query string
    SqlDataAdapter ad = new SqlDataAdapter(commandString,myConnection); 
    // DataSet instance created
    DataSet ds = new DataSet(); 
    // Fill DataSet 
    ad.Fill(ds,"Categories"); 
    try 
    { 
      // Opens database connection
      myConnection.Open(); 
      // Populate SlaveGrid
      SlaveGrid.DataSource = ds; 
      // Binds SlaveGrid to the page
      SlaveGrid.DataBind(); 
    } 

    // Catch SqlException 
    catch ( SqlException SqlEx ) 
    { 
      // TODO
    }
    // Catch general Exception
    catch ( Exception ex ) 
    {
      // TODO
    }
    // Closes the database connection
    finally { myConnection.Close(); } 
  } 
}