Array af controller

jeg har via http://msdn.microsoft.com/library/default.asp?url=/library/en-us/csref/html/vcwlkArraysTutorial.asp

lave flg. kode

LabelArray.cs indholder :

/*
* Created by SharpDevelop.
* User: Thomas
* Date: 13-10-2006
* Time: 10:18
*
* To change this template use Tools | Options | Coding | Edit Standard Headers.
*/

using System;

namespace lotto
{
    /// <summary>
    /// Description of LabelArray.
    /// </summary>
    public class LabelArray : System.Collections.CollectionBase
    {
        private readonly System.Windows.Forms.Form HostForm;
       
        public System.Windows.Forms.Label AddNewLabel()
        {
             
            // Create a new instance of the Button class.
              System.Windows.Forms.Label aLabel = new System.Windows.Forms.Label();
              // Add the button to the collection's internal list.
              this.List.Add(aLabel);
              // Add the button to the controls collection of the form
              // referenced by the HostForm field.
              HostForm.Controls.Add(aLabel);
              // Set intial properties for the button object.
              aLabel.Top = Count * 25;
              aLabel.Left = 100;
              aLabel.Tag = this.Count;
              aLabel.Text = "Label " + this.Count.ToString();
              aLabel.Click += new System.EventHandler(ClickHandler);
              return aLabel;
        }
       
        public LabelArray(System.Windows.Forms.Form host)
        {
              HostForm = host;
              this.AddNewLabel();
        }
       
        public System.Windows.Forms.Label this [int Index]
        {
            get
              {
                  return (System.Windows.Forms.Label) this.List[Index];
              }
        }
       
        public void Remove()
        {
            // Check to be sure there is a button to remove.
              if (this.Count > 0)
              {
                  // Remove the last button added to the array from the host form
                  // controls collection. Note the use of the indexer in accessing
                  // the array.
                  HostForm.Controls.Remove(this[this.Count -1]);
                  this.List.RemoveAt(this.Count -1);
              }
        }
       
        public void ClickHandler(Object sender, System.EventArgs e)
        {
                  System.Windows.Forms.MessageBox.Show("You have clicked label " + ((System.Windows.Forms.Label) sender).Tag.ToString());
        }
    }
}


og i min knap


        void Command1Click(object sender, System.EventArgs e)
        {
           
            byte xtel;
            //int atel;
           
           
            for(xtel=1;xtel<7;xtel++)
            {
                       
                MyControlArray.AddNewLabel();
                MyControlArray[(xtel-1)].BackColor = System.Drawing.Color.Red;
                locX += this.r.Width+20;
               
   
            }
           
        }


men når jeg klikker på knappen får jeg flg. fejl



Exception System.NullReferenceException was thrown in debuggee:
Object reference not set to an instance of an object.

Command1Click() - c:\Documents and Settings\Thomas\Dokumenter\SharpDevelop Projects\lotto\MainForm.cs:63,5
OnClick()
OnClick()
OnMouseUp()
WmMouseUp()
WndProc()
WndProc()
WndProc()
OnMessage()
WndProc()
DebuggableCallback()
System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop()
RunMessageLoopInner()
RunMessageLoop()
Run()
Main() - c:\Documents and Settings\Thomas\Dokumenter\SharpDevelop Projects\lotto\MainForm.cs:27,4

og denne linje bliver gul

MyControlArray.AddNewLabel();

når jeg siger den skal break;