' Override the CreateControlCollection method to 
' write to the Trace object when tracing is enabled
' for the page or application in which this control
' is included.   
Protected Overrides Function CreateControlCollection() As ControlCollection
    Return New CustomControlCollection(Me)
End Function

        // Override the CreateControlCollection method to 
        // write to the Trace object when tracing is enabled
        // for the page or application in which this control
        // is included.   
        protected override ControlCollection CreateControlCollection()
        {
            return new CustomControlCollection(this);
        }

Protected Overrides Sub CreateChildControls()
   ' Creates a new ControlCollection. 
   Me.CreateControlCollection()

   ' Create child controls.
   Dim firstControl As New ChildControl()
   firstControl.Message = "FirstChildControl"

   Dim secondControl As New ChildControl()
   secondControl.Message = "SecondChildControl"

   Controls.Add(firstControl)
   Controls.Add(secondControl)

   ' Prevent child controls from being created again.
   ChildControlsCreated = True
End Sub 'CreateChildControls

protected override void CreateChildControls()
{               
   // Creates a new ControlCollection. 
   this.CreateControlCollection();

   // Create child controls.
    ChildControl firstControl = new ChildControl();
   firstControl.Message = "FirstChildControl";

   ChildControl secondControl = new ChildControl();
   secondControl.Message = "SecondChildControl";

   Controls.Add(firstControl);
   Controls.Add(secondControl);

   // Prevent child controls from being created again.
   ChildControlsCreated = true;
}