RadioButton's CheckedChanged disappears after refresh

Question

I have a ASP.Net Page with a lot of dynamic generated controls at runtime. Each control is bound to a "Change Event". Everything works great except RadioButtons with the CheckedChanged event.

First time i visit the page all works fine. But the second time some RadioButtons have lost their CheckedChanged event.

Generated HTML Code on first page visit:

<input id="ctl00_masterContentPlaceHolder_question467b446b749c4252a4df1839ae81ee7fYesRadioButton" type="radio" name="ctl00$masterContentPlaceHolder$question467b446b749c4252a4df1839ae81ee7fRadioButtonGroup" value="question467b446b749c4252a4df1839ae81ee7fYesRadioButton" onclick="javascript:setTimeout('__doPostBack(\'ctl00$masterContentPlaceHolder$question467b446b749c4252a4df1839ae81ee7fYesRadioButton\',\'\')', 0)" tabindex="1">

<input id="ctl00_masterContentPlaceHolder_question467b446b749c4252a4df1839ae81ee7fNoRadioButton" type="radio" name="ctl00$masterContentPlaceHolder$question467b446b749c4252a4df1839ae81ee7fRadioButtonGroup" value="question467b446b749c4252a4df1839ae81ee7fNoRadioButton" onclick="javascript:setTimeout('__doPostBack(\'ctl00$masterContentPlaceHolder$question467b446b749c4252a4df1839ae81ee7fNoRadioButton\',\'\')', 0)">

After second visit (the onclick event from the second RadioButton is lost):

<input id="ctl00_masterContentPlaceHolder_question467b446b749c4252a4df1839ae81ee7fYesRadioButton" type="radio" name="ctl00$masterContentPlaceHolder$question467b446b749c4252a4df1839ae81ee7fRadioButtonGroup" value="question467b446b749c4252a4df1839ae81ee7fYesRadioButton" onclick="javascript:setTimeout('__doPostBack(\'ctl00$masterContentPlaceHolder$question467b446b749c4252a4df1839ae81ee7fYesRadioButton\',\'\')', 0)" tabindex="1">

<input id="ctl00_masterContentPlaceHolder_question467b446b749c4252a4df1839ae81ee7fNoRadioButton" type="radio" name="ctl00$masterContentPlaceHolder$question467b446b749c4252a4df1839ae81ee7fRadioButtonGroup" value="question467b446b749c4252a4df1839ae81ee7fNoRadioButton" checked="checked">

Edit

Controls are added inside the Page_Load event:

System.Collections.Generic.List<CPM.Arda.Questionnaire.Base.Objects.QuestionRenderResult<System.Web.UI.Control>> questionRenderResults = _questionnaireParser.Render(questionnaireGroup, false);
            foreach (CPM.Arda.Questionnaire.Base.Objects.QuestionRenderResult<System.Web.UI.Control> questionRenderResult in questionRenderResults)
                questionnaireGroupControlsPanel.Controls.Add(questionRenderResult.QuestionControl);

Code inside the Render() method:

    System.Web.UI.WebControls.RadioButton yesRadioButton = new System.Web.UI.WebControls.RadioButton();
    yesRadioButton.ID = "question" + questionnaireGroupQuestion.Id.ToString().Replace("-", "") + "YesRadioButton";
    yesRadioButton.Text = "Ja";
    yesRadioButton.GroupName = "question" + questionnaireGroupQuestion.Id.ToString().Replace("-", "") + "RadioButtonGroup";
    yesRadioButton.TabIndex = tabIndex;
    yesRadioButton.Enabled = !_readOnly;
    yesRadioButton.AutoPostBack = true;
    yesRadioButton.CheckedChanged += inputControl_ValueChanged;

    System.Web.UI.WebControls.RadioButton noRadioButton = new System.Web.UI.WebControls.RadioButton();
    noRadioButton.ID = "question" + questionnaireGroupQuestion.Id.ToString().Replace("-", "") + "NoRadioButton";
    noRadioButton.Text = "Nein";
    noRadioButton.GroupName = "question" + questionnaireGroupQuestion.Id.ToString().Replace("-", "") + "RadioButtonGroup";
    noRadioButton.Style.Add("margin-left", "10px");
    noRadioButton.Enabled = !_readOnly;
    noRadioButton.AutoPostBack = true;
    noRadioButton.CheckedChanged += inputControl_ValueChanged;

Can anyone explain this?

Answer 1

Found a solution for my problem.

Seems to be a bug in AjaxToolKit. Look at this:

ASP.NET Radio button checked changed event not firing for first radio button

Worked for me.