1. Introduction
2. Real World Example
3. A Better Way
4. Putting it All Together

Comments

1. ASP_Man
   31 Dec 2003 at 13:13

   I am getting as error message of
   

   
       C:\Program Files\ASP.NET Starter Kits\ASP.NET Portal (CSSDK)\PortalCSSDK\RegDataGrid.cs(20): The type or namespace name 'DataSource' could not be found (are you missing a using directive or an assembly reference?)
   

   
       and
   

   
       C:\Program Files\ASP.NET Starter Kits\ASP.NET Portal (CSSDK)\PortalCSSDK\RegDataGrid.cs(54): The type or namespace name 'DataGridItemEventArgs' could not be found (are you missing a using directive or an assembly reference?)
   

   
   when running the code. What am I missing?
   

   
   Here is the code I am running.
   

   
   using System;
   

   
   namespace ASPNET.StarterKit.Portal
   {
      /// <summary>
      ///
      /// </summary>
      public class RegDataGrid : System.Web.UI.WebControls.DataGrid
      {
          public RegDataGrid()
          {
              //
              // TODO: Add constructor logic here
              //
          }
   

   
          // Class member that stores the index of the "Delete" column of this grid
          protected int delcol = -1;
   

   
          protected override ArrayList CreateColumnSet(PagedDataSource dataSource, bool useDataSource)
          {
              // Let the DataGrid create the columns
              ArrayList list = base.CreateColumnSet (dataSource, useDataSource);
   

   
              // Examine the columns
              delcol=0;
              foreach (DataGridColumn col in list)
              {
                  // If this column is the "Delete" button command column...
                  if ((col is ButtonColumn) && (((ButtonColumn)col).CommandName == "Delete"))
                  {
                      // Found it
                      break;
                  }
   

   
                  delcol++;
              }
   

   
              // If we did not find a delete column, invalidate the index
              if (delcol == list.Count) delcol = -1;
      
              // Done
              return list;
          }
   

   
          // Property to enable/disable deletion confirmation
          protected bool confirmdel = true;
          public bool ConfirmOnDelete
          {
              get { return confirmdel; }
              set { confirmdel = value; }
          }
   

   
          protected override void OnItemDataBound(DataGridItemEventArgs e)
          {
              // Create it first in the DataGrid
              base.OnItemDataBound (e);
   

   
              // Attach javascript confirmation to the delete button
              if ((confirmdel) && (delcol != -1))
              {
                  e.Item.Cells[delcol].Attributes.Add("onclick", "return confirm('Are you sure?')");
              }
          }
          
      }
   }

2. Elliot Rodriguez
   06 Oct 2003 at 07:26

   Mick:
   

   
   shoot me an email at elliotmrodriguezathotmaildotcom and I will send you the class file. Perhaps we can work together on this.
   

   
   Oddly enough, when I compile (without errors) and set a reference to the file in my web page, the grid never gets displayed. I've stepped through the code on the webpage that sets its properties, and they work fine; Intellisense shows my properties for the class, so I know its being seen, but none of the events in the class itself get called. I am perplexed.
   

   
   Greg Ennis, can you also help?

3. kali_mist
   06 Oct 2003 at 06:10

   Hi Elliot,
   Is there any chance that you can show me the code for the derived datagrid in VB.net.
   Im having trouble creating it myself. Im new to this subclassing stuff.
   Thank you
   

   
   Mick Lennon
   Louth
   Ireland

4. Elliot Rodriguez
   03 Oct 2003 at 13:54

   You have to add the class manually as a generic class, then use the Inherits statement
   

   
   Public Class DeleteDataGrid ' or whatever you want to call it
      Inherits System.Web.UI.WebControls.DataGrid
   

   
   Hitting ENTER after the Inherits statement will make the stubs appear automagically for both CreateControlHierarchy and PrepareControlHierarchy. OnItemDataBound, however, does not show up; you will have to add the function signature yourself.
   

   
   HTH
   

   
   

5. Elliot Rodriguez
   03 Oct 2003 at 13:51

   great article. I was able to implement the grid in VB.NET quite easily, and I plan on extending it in similar fashion to create DataGrids with selectable rows. Thanks Greg!

6. jspadea
   03 Oct 2003 at 11:20

   I'm using VB.NET 2003 and I don't see the "Add" option when I right click in the Class view either.

7. sbguy
   30 Sep 2003 at 23:13

   Great article, but am I missing something. I go into Class view, but I get no "Add" option when I right-click on the project. This is an ASP.Net (VB.Net) project, so is it the case that this is not available in ASP.Net projects?

8. Developer Fusion Bot
   01 Jan 1999 at 00:00

   This thread is for discussions of Object-Oriented ASP.NET.