> I have a CompositeControl (called SimplePager) that creates an
> UpdatePanel in its CreateChildControls override.  The CompositeControl
> uses two LinkButtons to control the forward/backward state.  W/out the
> use of the UpdatePanel it works just great.  However, as a learning
> exercise I want to AJAXify the control.  I am placing the entire
> control in an UpdatePanel.  During the link click event handler, I
> make a call to RecreateChildControls() which throws an exception.
>
> This is so close to working.  Can someone suggest how to accomplish
> what I am trying to do with an UpdatePanel?
>
> My class is copied below.
>
> Thanks,
> John
>
>     public class SimplePager : CompositeControl
>     {
>         private int _currentRecord;
>         private int _totalRecords;
>
>         public SimplePager(int totalRecords)
>         {
>             _totalRecords = totalRecords;
>             _currentRecord = 1;
>         }
>
>         protected override void OnInit(EventArgs e)
>         {
>             Page.RegisterRequiresControlState(this);
>
>             EnsureChildControls();
>
>             base.OnInit(e);
>         }
>
>         protected override void LoadControlState(object savedState)
>         {
>             int[] state;
>
>             state = (int[])savedState;
>
>             _currentRecord = state[0];
>             _totalRecords = state[1];
>         }
>
>         protected override object SaveControlState()
>         {
>             int[] state;
>
>             state = new int[] { _currentRecord, _totalRecords };
>
>             return state;
>         }
>
>         protected override void CreateChildControls()
>         {
>             HtmlGenericControl div;
>             LinkButton linkButton;
>             UpdatePanel updatePanel;
>             Label label;
>
>             div = new HtmlGenericControl("div");
>             Controls.Add(div);
>
>             updatePanel = new UpdatePanel();
>             updatePanel.ID = this.ID + "BWPagerUpdatePanel";
>             updatePanel.ChildrenAsTriggers = true;
>             updatePanel.UpdateMode =
> UpdatePanelUpdateMode.Conditional;
>             div.Controls.Add(updatePanel);
>
>             linkButton = new LinkButton();
>             linkButton.Text = "<< prev";
>             linkButton.ID = "prevPage";
>             linkButton.Click += new EventHandler(linkButton_Click);
>
> updatePanel.ContentTemplateContainer.Controls.Add(linkButton);
>
>             linkButton = new LinkButton();
>             linkButton.Text = "next >>";
>             linkButton.ID = "nextPage";
>             linkButton.Click += new EventHandler(linkButton_Click);
>
> updatePanel.ContentTemplateContainer.Controls.Add(linkButton);
>
>             label = new Label();
>             label.ID = "SimplePagerTextBox";
>             label.Text = String.Format("&nbsp;&nbsp;Page {0} of {1}",
> _currentRecord, _totalRecords);
>             updatePanel.ContentTemplateContainer.Controls.Add(label);
>
>             base.CreateChildControls();
>         }
>
>         private void linkButton_Click(object sender, EventArgs e)
>         {
>             LinkButton linkButton = sender as LinkButton;
>
>             if (PageChange != null)
>             {
>                 switch (linkButton.ID)
>                 {
>                     case "prevPage":
>                         if (_currentRecord > 1)
>                             _currentRecord--;
>                         break;
>
>                     case "nextPage":
>                         if (_currentRecord < _totalRecords)
>                             _currentRecord++;
>                         break;
>                 }
>
>                 PageChange(this, _currentRecord);
>
>                 RecreateChildControls();
>             }
>         }
>
>         public int CurrentRecord
>         {
>             get
>             {
>                 return _currentRecord;
>             }
>         }
>
>         public delegate void PageChangeEvent(object sender, int
> newPage);
>         public event PageChangeEvent PageChange;
>     }