getting postback events to fire for dynamically added custom controls

I recently posted regarding these 2 controls, but this is a completely different issue, so I thought it best to start a new thread.

I have two composite controls (neither renders content, rather they add controls to the control tree). Control X is declared on the page and is passed a custom collection. X iterates through this collection and creates a tab and a 'pane' for each item in the collection. To each pane it adds an instance of control Y, which contains a couple of textboxes and a hidden inputbox.
My problem is:
if I have a std button on the page which posts back, I need the instances of Y to keep (and update) their state. I can't get any postback events to raise on the instances of Y - they just seem to create new instances of themselves (with the same name on each form element). I'm calling the EnsureEventsHiddenInputBox method in Y's OnPreRender method.
At the moment i'm supplying Y with it's 'source' collection in the aspx Init, whether it's a postback or not. Is this part of the issue? Should I be storing the state of X (including all info about each Y) in X?
I've written a few server controls now, all of which are much more complex than this one, but I just can't get my head around this for some reason...
Any tips before I resort to hardcoding everything into the aspx?!
4/16/2004 12:59:59 PM 4216 articles. 0 followers. Follow

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Haven't a clue as to understanding what you are really doing but a few things do come to mind, that may or may not make a difference. 1.)Besure to assign ID's to them durring the init creation process... I am guessing but it may affect something if the ID's are getting generated later in the processing. 2.) Are all the panels visible ? Doesn't that affect the rendering and saving of viewstate just a guess but could be an issue. It's not going to save viewstate of a control that isn't render(atleast I don't think so lol). GoodLuck
Answering a question increases your knowledge asking a question shows your Intelligence!
4/16/2004 1:52:26 PM
Yes, I have a tip :-) .

The trick over there in your composite control is to recreate all the controls before the end of the Load event. So you should have some code like so:

protected override void OnLoad(EventArgs e) {
EnsureChildControls(); // assuming that you build the control tree under CreateChildControls method
base.OnLoad(EventArgs e);

In fact, I recommend that you do that in the Init part of the life cycle; however, it all depends on how much your control knows at each stage of the life cycle.
-- Justin Lovell
4/17/2004 12:35:10 PM
thanks guys, much appreciated.  I think you may both be onto something.  If I get a chance i'll try adding them in Init and see if it makes any difference.

As it happens I sort of went back to basics to solve it. As i'm creating each instance of Y I know what each form element's name/id will be (within Y), so I just assign the values from the form post (if an item exists) for each element.
It may not be a very '.Net' way of doing things, but I think it's actually better as I don't have to use viewstate, deal with postback in the control etc.
Anyway, thanks again for your help.
4/20/2004 2:48:33 PM
and i've just discovered the downside to this way of doing it!  (if you set visible to false on postback, the form elements aren't written to the page [obviously...] and the control resets itself to blank values on the next postback)

Back to the drawing board...
4/20/2004 4:34:44 PM
In place of making the panels visible, can you set the width to 1?  The intent is for them to be drawn on the form but not be visible.
4/25/2004 12:44:23 AM

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