Hello,

I'm fairly new to .NET and c# so I apologize in advance if this is a basic question :)

I'm having trouble using dynamic Controls and reading the associated user-selections in my code-behind:

I'm attempting to build a web application that presents to the user a dynamic list of questions and possible user-selected responses. The data-driven list of questions may each contain a True/False radio selections and/or a free form textbox (for instance). I'd like to display the questions in Step 1, re-present read-only versions of the questions and user selections upon submission in Step 2, and after the user confirms the validity of his/her selections, confirm the database write action in Step 3 - all three steps using the same .aspx page utilizing <ASP:Panel> objects to display and hide the objects for each of the steps.

To manifest these list of questions and the possible responses in Step 1 I decided to employ the use of a mixture of User Controls and basic Web Controls added to a Panel object via

MyPanel.Controls.Add( MyControl );

(I'm told there is little functional distinction in my context between the User Controls and Web Controls and it is really a design choice) - for instance I use Label and TextBox Web Controls and a User Control that contains a RadioButtonList for which I attach a DataSource dependent on the Question characteristics (this gives me a dynamic list of radio selections dependent on the characteristics of the Question - I was really pleased with how easy this was to do in .NET).

After much effort, I'm able to render my list of questions and possible responses successfully (recall I said I was fairly new to .NET and C# :) ). However, I run into trouble when I try to extract the user-selections from the Radio selections and the TextBoxes in Step 2. I've tried to pull the dynamic objects from my Panel via

MyPanel.FindControl("MyObjectId")

but to no avail. Also, I've tried to loop through the Panel objects via

foreach(Control tmpControl in MyPanel.Controls)

I've tried this in my submit action callback routine as well as an overriding OnPreRender routine but this doesn't quite work either. (I can successfully loop through the dynamic panel objects when Rendering the page for Step1 but this doesn't work when rendering Step 2 because I've remove the user-selection objects from Step1 so I can make room for the display of the read-only user-selection values for review in Step 2 - the trouble is I can't seem to extract the user-selections from Step 1 for display in Step 2.)

I've also tried to loop through MyPanel.Controls in Page_Load and, again, when transitioning from Step 1 to Step 2 I'm not seeing the dynamic objects.

I must be doing something wrong because this seems like a pretty basic capability to have: adding dynamic controls to a panel and being able to extra user-selections. What I'm I doing wrong? Should I be looping through my panel in another event routine? Let me know if any code snipets would be illustrative.

Thank you, thank you, thank you!

David

Hi David,

First of all, at least you do not have the "ignorance" of not trying. Whether or not the question is basic or not, people are always glad to help the people you try their hardest on their side... and I admire that facet -- I do get annoyed with the simple questions but the reason is that most of the people have an attitude attached to their posts (it is worse than being just lazy). And this is why I post so much -- to find rare people like you.

Ok, to the question at hand. What I would have done is built a composite control. But nevermind, there will just be more "ugleness" attached :-) . What you have to do, when you hit step two, is recreate the same form that you did in step one first (there must be no deviations). And from here is when you create your second "page". To get the values from step one, you can do it the two ways that you have mentioned above.

And by now, you will probably be asking "why recreate the step one in step two? It will just show step one amongst step two..." Ah - this is where some really nice magical code gets splashed up. Put the following code in your page:

protected override void OnPreRender(EventArgs e) {


   stepOnePanel.Visible = false;


   base.OnPreRender(e);


}

I think that will solve your problem with the side-by-side display which you probably picked up on in the second paragraph of the post.

Yours,
Justin

---

-- Justin Lovell

Hi Justin,

Your suggestion has certainly helped me move the ball a bit further down the field :). I recreated the panel objects during Step 2 using the same routine originally used in Step 1 and included the OnPreRender() routine you suggested. The good news... I can now "see" all of the objects I created using the foreach() loop (oddly the FindControl() method still does not return a 'hit'). When stepping through in debug mode I can see each of my attempts to pull values from each of the dynamic objects. The bad news... the values don't seem to contain the user-selections from Step 1. It is as though the objects were re-initialized when I recreated them at the start of Step 2. (By the way, the OnPreRender() routine successfully removes the Step 1 panel - pretty cool).

Is there something else I need to do to have the re-created objects "grab" the user-selections from Step 1?

Thanks again in advance Justin. By the way, I've been reading these forums for only a week or so but I see your name everywhere :) I for one certainly appreciate the "volunteer" work you do for everyone :)

David.

Hi Justin,

I had another opportunity to work on this since my last posting. I took you suggestion to heart about re-creating the dynamic objects "exactly" the same way in Step 2 as was done in Step 1. While I was using the same routine to re-create I was doing it in different event handlers. So I moved the re-creation routine call to the Page_Load routine so the objects are created each time through (with the hiding of the Step 1 panel in the OnPreRender() routine as you suggested originally it was not a worry about re-creating "too often"). When I tested it with the re-creation if the Page_Load all works perfectly!!! I can see the user-selections displayed in my Step 2 panel! From here it should be rather trivial to manipulate and utilize the user-selections as originally hoped.

Thanks again for setting me on the correct path!

Cheers!

David.

Glad that I could help out David. Have fun!

---

-- Justin Lovell