asp.net dynamic control values on postback

Question

In an asp.net web forms application I am pulling in a random set of up to 2 questions and up to 3 answers (for each question) from an SQL database. For each question I am dynamically creating a RadioButtonList control to hold the set of answers.

When a postback is triggered I need to read the value of each RadioButtonList. I don't need to retain the control itself just the selected index/value because a new (different) set of questions and answers will be created if an answer is wrong and the user gets redirected to a new page if the answers are correct.

I have tried to re-create the controls in the Page_init event during the postback but because my dynamic controls are created based on a random set of data, they will be different each time.

Dynamic control creation on Page_Load:

foreach (DataRow question in dt_questions.Rows)
{
    questionCounter++;

    RadioButtonList RBL_Answers = new RadioButtonList();
    RBL_Answers.ID = "RBL_Answers_" + questionCounter;

    // fill radio list with answers to pick from
    foreach (DataRow answer in dt_answers.Rows)
    {
        ListItem item = new ListItem(answer["IA_Text"].ToString(), answer["IA_Correct"].ToString());
        RBL_Answers.Items.Add(item);
    }

    Panel_ContentQA.Controls.Add(RBL_Answers);
}

score 0 · Answer 1 · answered May 06 '14 at 00:16

To solve the issue I had to change the way I was doing things so that the primary key ID's of the (random) rows from the SQL database for the controls that are created on the page are stored in the ViewState. When a postback occurs, the controls are then recreated sourcing the same data from SQL that corresponds with the PK's stored in ViewState.

asp.net dynamic control values on postback

1 Answers1