Solved

Server controls inside a composite control do not fire events within control

Posted on 2007-11-16
2
652 Views
Last Modified: 2012-08-13
With much pain i have created a custom control which renders the control with a decent look and feel. I could possibly handle that. But the matter of concern is that the server controls (i have many listbox to name one) are not invoking any events. I will explain more about the custom control. It is quite a simple custom control that inherits from CompositeControl and INamingContainer. The control has an asp.net button and an asp.net listbox server control. In the CreateChildControls method of the CustomControl - ImagePicker is its name, i have associtated the selectedindexchanged event on the listbox. The behaviour at runtime is weird. The page which hosts the CustomControl posts back successfully, but the event is never invoked. Note that the event handler is also inside the control itself. I am not talking about exposing the events to the external world which i know will require me to implement the interfaces IPostBackDataHandler and IPostBackEventHandler. I have infact implemented those interfaces just in case i understood it wrong, but it wont help.
Following is the code that i added in CreateChildControls method:

            listCategories = new ListBox();
            listCategories.Height = Unit.Pixel(120);
            listCategories.AutoPostBack = true;
            listCategories.BackColor = Color.Gray;
            listCategories.BorderStyle = BorderStyle.None;
            listCategories.BorderWidth = 0;
            listCategories.EnableViewState = true;
            this.Controls.Add(listCategories);
            listCategories.SelectedIndexChanged += new EventHandler(listCategories_SelectedIndexChanged);

The method listCategories_SelectedIndexChanged is never fired. Neither the SelectedIndex of the listbox gets changed.
0
Comment
Question by:sudhijss
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 33

Expert Comment

by:raterus
ID: 20300468
Just go ahead and post all the code of your composite control, and all the code of the aspx page you are using this control in.  It is possible to do what you want without anything too fancy.
0
 
LVL 1

Accepted Solution

by:
sudhijss earned 0 total points
ID: 20301016
Got it! Must have been a stupid mistake i guess. I was adding items to the list inside the RenderContents method. I moved that databinding code to the CreateChildControls and lo the event fires. I must ve not understood the page lifecycle appropriately. Thanks for offering help anyway.
0

Featured Post

On Demand Webinar - Networking for the Cloud Era

This webinar discusses:
-Common barriers companies experience when moving to the cloud
-How SD-WAN changes the way we look at networks
-Best practices customers should employ moving forward with cloud migration
-What happens behind the scenes of SteelConnect’s one-click button

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article is for Object-Oriented Programming (OOP) beginners. An Interface contains declarations of events, indexers, methods and/or properties. Any class which implements the Interface should provide the concrete implementation for each Inter…
Entity Framework is a powerful tool to help you interact with the DataBase but still doesn't help much when we have a Stored Procedure that returns more than one resultset. The solution takes some of out-of-the-box thinking; read on!
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…
In an interesting question (https://www.experts-exchange.com/questions/29008360/) here at Experts Exchange, a member asked how to split a single image into multiple images. The primary usage for this is to place many photographs on a flatbed scanner…

730 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question