FindControl() not finding control

Question

I have a website that is dynamically creating HiddenFields for each item inside a Listbox.

foreach (Checklist c in check)
{
    lbxCheckListLevel3.Items.Add(c.Name);
    HiddenField hf = new HiddenField();
    hf.ID = c.Name;
    hf.Value = c.Status + ":" + c.ResponseLabels + ":" + c.Prompt + ":" + c.Notes + ":" + c.ResponseValues;
    prompt.Controls.Add(hf);
}

The value of the HiddenField is being changed inside Javascript

And then when the save button is clicked, the OnClick function runs to go through all the HiddenFields and read the Values back out.

for(int i = 0; lbxCheckListLevel3.Items.Count > i; i++)
{
   //Update the main checklist with the new information                
   HiddenField hidden = (HiddenField)FindControl(lbxCheckListLevel3.Items[i].Text);
   int index = check.FindIndex(delegate(Checklist c) { return c.Name == lbxCheckListLevel3.Items[i].Text; });
   if (check[index].Status != int.Parse(hidden.Value.Split(':')[0]) || 
      check[index].Notes != hidden.Value.Split(':')[3] ||
      check[index].ResponseValues != hidden.Value.Split(':')[4]) 
   {
      check[index].Status = int.Parse(hidden.Value.Split(':')[0]);
      check[index].Notes = hidden.Value.Split(':')[3];
      check[index].ResponseValues = hidden.Value.Split(':')[4];
      check[index].Changed = true;
   }
}

My problem, is that the FindControl Line returns NULL. I have brought up Developer tools in IE9 and made sure that it exists and with the correct ID. But it still returns the NULL

If you need anymore information, please ask, and I will do the best I can.

EDIT

The following line is the culperate, I believe because of the dash. Even though it is shown in ID of the Field

Environmental Health – Does the application involve any of the following:

Javascript is still able to find the control and change the values.

I have found another with a dash, and that one is being found without error. Seems to be this line only...

Please see this as it is similar to yours. http://stackoverflow.com/questions/7495486/button-click-event-not-firing-within-use-control-in-asp-net/7495550#7495550 — Valamas, May 03 '12 at 23:40
Ok, the summary is, you need to make sure your hidden boxes exist so that viewstate can be bound back to the control. Therefore, recreate your controls in the page_load event. — Valamas, May 04 '12 at 00:08
The hiddenFields definatly exist. Making sure they do, i have found other/real error. It only happens on selected Items. Is there specific characters that will not go into ID or match with the FindControl function for some reason? — Seige, May 04 '12 at 00:33

score 1 · Answer 1 · answered May 04 '12 at 00:23

1

not only what others have suggested you is valid and you should be sure your controls are recreated at Page_Init or Page_Load, also consider that you are adding your controls to the: prompt.Controls so make sure you search in the right container, for example try searching like this:

HiddenField hidden = (HiddenField)prompt.FindControl(...);

only in this way you are sure you search in the same container as you added your HiddenField before.

answered May 04 '12 at 00:23

Davide Piras

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I will modify code and add this. See update for more information. – Seige May 04 '12 at 00:38

FindControl() not finding control

1 Answers1