Hi

I'm using a Composite pattern for user controls on a project with a custom httphandler. There is one common component that all the controls inherit from including the composite control. The composite is also a user control that simply ties all the others together and takes care of event handling between them. Anyway, some of these controls are inside UpdatePanels in the composite and when I try to recursively traverse down the control tree, I cant get a reference to the user controls that are inside UpdatePanels. I can access them directly from the codebehind of the composite but that's exactly what the recursive function is trying to avoid. I do get a reference to the UpdatePanel themselves but using a FindControl to get at the user control inside returns a null. The updatePanel.Controls.Count is always 0 and I cant find any information about the SingleChildControlCollection to see how that ought to work.

 Any advice?

Thanks.

Here is how I handle it.  Sometimes depending on how the controls are used or the properties of the control - when in codebehind its difficult to find a control within a control if it hasn't been rendered...Wizard Control for instance - if it contains custom controls you have to do more than the typical find control.  This is the code I use for those scenarios:

 Place in Base Class...

 public Control GetNestedControl(Control skin, string controlID)
        {
            Control ctlFoundControl = null;
            try
            {
                ctlFoundControl = base.FindControl(controlID);
            }
            catch(HttpException)
            {
                ctlFoundControl = null;

            }
           return (ctlFoundControl != null) ? ctlFoundControl : GetNestedControl(skin.Controls, controlID);

        }

        public static Control GetNestedControl(ControlCollection col, string id)
        {
            foreach (Control c in col)
            {
                Control child = FindNestedControl(c, id);
                if(child !=null)
                    return child;


            }
            return null;
        }
        private static Control FindNestedControl(Control root, string id)
        {
            if (root.ID != null && root.ID == id)
            {
                return root;
            }

            foreach (Control child in root.Controls)
            {
                Control recurse = FindNestedControl(child, id);
                if (recurse != null)
                { return recurse; }
            }
            return null;

        }

To use in your  control:

On the init or wherever you start the process:

 override protected void InitializeSkin(Control skin)
        {

                Wizard1 = (Wizard)GetControl(skin, "Wizard1"); <--this is the control we can't use the typical FindControl

// the following are in the navigation panes use GetNested instead of GetControl

               chkConfirmAction = (CheckBox)GetNestedControl(skin, "chkConfirmAction"); <-
    

Maybe that will help you in this situation - maybe not :)

Hey Jody

From what you said, I thought about EnsureChildControls(), which I cant use explicity, since the Composite control is also a UserControl. But this seemed to do it..

 On the aspx, this is how it was earlier where i could access all controls inside the composite and inside the usercontrols in the composite except those inside UpdatePanels

Control ctrl = LoadControl( composite user control );
ctrl.SetData( some object );
if( not a postback )
      this.something.Add( ctrl );

I've read about this somewhere and revered the statements order, like this

Control ctrl = LoadControl( composite user control );
if( not a postback )
       this.something.Add( ctrl );
ctrl.SetData( some object );

 And now i can see the controls inside UpdatePanels. Strange but it works.

Thanks a lot,
vik