RadioButtonList, Web User Control, Firefox, IE




I have a radiobuttonlist control that is added on a custom Web User Control.
This control has a property that exposes the SelectedIndex property of the
embedded radiobuttonlist.

When running this in IE, behaviour is as I would expect it. If I select an
item and do a postback, the page remembers my selection when reloading, and
the SelectedIndex property of my control returns the correct value.

When running this in Firefox 3, I always get a -1 for the SelectedIndex
prop, and the page does not remember my selection when reloading.

If I add a radiobuttonlist directly on to an ASPX page, behaviour is as
expected. Only fails in Firefox when the control is on a custom Web User

Below I will paste the aspx, ascx, and their respective code behind files.
..Net Framework 3.5. Any advice would be appreciated.


1. FF.aspx

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="FF.aspx.vb"
Inherits="FF" %>

<%@ Register Src="TEST.ascx" TagName="TESTcontrol" TagPrefix="uc1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

<html xmlns="">
<head runat="server">
<title>Untitled Page</title>
<form id="form1" runat="server">

<asp:placeHolder ID="PlaceHolder1" runat="server"></asp:placeHolder>

<asp:Button ID="Button1" runat="server" Text="Button" Width="55px" />

2. FF.aspx.vb

Partial Class FF
Inherits System.Web.UI.Page
Protected WithEvents rbl As test
Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Me.Load
rbl = CType(Me.LoadControl("TEST.ascx"), TEST)
rbl.ID = "rblID99"
End Sub
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Button1.Click
End Sub
Sub Check(ByVal _control As Control)
If _control.ID IsNot Nothing Then
If _control.GetType.ToString =
"System.Web.UI.WebControls.RadioButtonList" Then
RadioButtonList).SelectedIndex & " - selected index<br/>")
If CType(_control, RadioButtonList).SelectedIndex < 0 Then
MsgBox("Not checked.", MsgBoxStyle.ApplicationModal,
End If
End If
End If
If _control.HasControls Then
For Each ctrl As Control In _control.Controls
End If
End Sub
End Class

3. TEST.ascx

<%@ Control Language="VB" AutoEventWireup="false" CodeFile="TEST.ascx.vb"
Inherits="TEST" Classname="TEST"%>

<p style="width: 500px">

<asp:Label ID="Question_TXT" runat="server">Q</asp:Label>
<p style="width: 500px">
<asp:RadioButtonList ID="Answer_RBL" runat="server">

4. TEST.ascx.vb

Partial Class TEST
Inherits System.Web.UI.UserControl
Public ReadOnly Property SelectedIndex() As Integer
Return Answer_RBL.SelectedIndex
End Get
End Property

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Me.Load
Question_TXT.Text = "Pick One"
Answer_RBL.Items(0).Text = vbTab & "First"
Answer_RBL.Items(1).Text = vbTab & "Second"
End Sub
End Class



bruce barker

its a bug in IE, it should send -1 also.

you are loading the user control too late in the page lifecycle, so that it
does not exist when postback data is applied. the proper place to load
dynamic controls is in the CreateChildControls method (which was designed for
this, or OnInit in a pinch)

-- bruce (

Teemu Keiski


moving the code to create the control to OnInit or CreateChildControls
doesn't change the thing, ASP.NET is able to load postback data for controls
loaded in Page_Load (postback data loading happens in two steps once before
and once after Load - you can cofirm that by checking page trace).

By the way, for testing purposes maybe OK, but don't use MSgBox in ASp.NET
in production as it shows the MSgBoxes only on the server machine...

The issue itself relates that you add vbTab to the ListItem's Text in code:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Me.Load
Question_TXT.Text = "Pick One"
Answer_RBL.Items(0).Text = vbTab & "First"
Answer_RBL.Items(1).Text = vbTab & "Second"
End Sub

Remove the vbTab appendings and you'll note the thing starts to work just
fine (with control loaded in Page_Load, although in practise doing it in
Init or CreateChildControls eases certain things in the long run.

So I suppose it relates to other browser dealing with the tab...

Teemu Keiski
AspInsider, ASP.NET MVP

Teemu Keiski

To add, the issue still occurred in my test case even when creating the
control in CreateChildControls, when ListItem had vbTabs.


Steven Cheng [MSFT]

Thanks for your Teemu's informative inputs.

Seems the problem is related to the firefox 3's handling on <select>
options which contains tab chars. BTW, I agree that "OnInit" and
"CreateChildControls" are the prefered place for dynamic controls though it
may not address the problem here.


Steven Cheng

Microsoft MSDN Online Support Lead

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From: "Teemu Keiski" <[email protected]>
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Hi Teemu,

Fantastic. So simple, and I spent so much time trying to track this down.
Your help is appreciated. Thanks as well Bruce and Steven.

By the way, in the sample I load the controls in the Page Load event, but in
my actual page I load it in PreInit.

Thanks again


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