Question

I have seen many others with similar problems but I cannot find the flaw in my logic here. Any help would be greatly appreciated.

I have a Panel which I have added numerous label and textbox controls to, ie:

myPanel.Controls.Add(txtBox);

These controls are created and added in a method called previous to the iteration method.

I want to iterate through each textbox and use its Text property as a parameter in another method but I am not having any luck. Here is my attempt to iterate:

public void updateQuestions()
{
    try
    {
        foreach (Control c in editQuestionsPanel.Controls)
        {
            if (c is TextBox)
            {
                TextBox questionTextBox = (TextBox)c;

                string question = questionTextBox.Text;

                writeNewQuestionToTblQuestions(question);
            }
        }
    }
    catch (Exception err)
    {
        Console.WriteLine(err.Message);
    }
}

The problem I am having is that the controls are not in the Panel when I arrive at this updateQuestions() method. Here is the process involved:

A commandButton is clicked and the questions are read from a DB, for each question a method is called which adds 2 labels and a textbox to editQuestionsPanel.Controls. This panel is inside a PlaceHolder which is then made visible.

When a button inside the PlaceHolder is clicked, the updateQuestions() method is called and the editQuestionsPanel.Controls.Count = 1. As there are approx 12 questions in the DB it should be around 36. The one control inside the Panel is of type:

System.Web.UI.LiteralControl  

It contains no controls.

I am sure that somwhere in the lifecycle the Panel’s controls are being cleared but I do not know how to step thru the life cycle. I have a Page_load method which is called as soon as a button is clicked but once the button which calls updateQuestions() is clicked the editQuestionsPanel.Controls.Count is already back to 1 so it must be cleared before this but I do not know how to correct this…

Any help you can give to help me solve this would be greatly appreciated – its killing me!

Answer 1

When you add controls dynamically, you need to do that on every request – asp.net doesn’t do that for you!

Add the controls in the Init or Load phase, then they will get populated with the postback values.