DOCUMENT:Q191720  24-AUG-1998  [vbwin]
TITLE   :BUG: Option Button Value Changes When Group is Disabled
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:
OPER/SYS:WINDOWS
KEYWORDS:

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The information in this article applies to:

 - Microsoft Visual Basic Learning, Professional, and Enterprise Editions
   for Windows, versions 5.0, 6.0
 - Microsoft Visual Basic Standard, Professional, and Enterprise Editions,
   16-bit and 32-bit, for Windows, version 4.0
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SYMPTOMS
========

You have a group of Option Buttons on a Visual Basic Form. When you disable
them from code, the last one disabled will have its Value property changed
to True, causing the Click event for that button to fire. This occurs only
when all of the option buttons are disabled.

CAUSE
=====

The problem occurs when the buttons are disabled while the current input
focus is on one of the buttons. As each button is disabled in turn, the tab
order advances the focus to the next available button in the option group.
When the last button is disabled, its Value property is set to True, and
its Click event is fired.

RESOLUTION
==========

This behavior does not occur if the input focus is moved to another control
before the buttons are disabled.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed
at the beginning of this article.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

1. Create a new Standard EXE project. Form1 is created by default.

2. Add three Option Buttons to Form1.

3. Paste the following code into Form1's code window:

      Option Explicit

      Private Sub Form_Load()
          Option2.Value = True
      End Sub

      Private Sub Form_DblClick()
         Option1.Enabled = False
         Option2.Enabled = False
         Option3.Enabled = False
      End Sub

      Private Sub Option3_Click()
         MsgBox "Option3 Click"
      End Sub

4. Run the project by pressing the F5 key. When the program starts, the
   input focus is set to Option2.

5. Double-click somewhere on Form1. Note that the Click event for Option3
   is fired when the button is disabled.

6. To resolve the problem, add a Text Box to Form1. Then add the following
   line at the start of the Form_DblClick event:

      Text1.SetFocus

7. Re-run the program and double-click somewhere on Form1. This time the
   Click event of Option3 should not fire when the control is disabled.

Additional query words: kbDSupport kbDSD radio kbVBp kbvbp400bug
kbVBp600bug kbVBp500bug kbVBp kbdsd
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Platform          : WINDOWS
Issue type        : kbbug

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