Q195273: FIX: Fatal Exception C0000005 When Removing Form from a Formset

Article: Q195273
Product(s): Microsoft FoxPro
Version(s): WINDOWS:6.0
Operating System(s): 
Keyword(s): kbContainer kbCtrl kbvfp600 kbvfp600bug kbVS600sp3fix kbGrpDSFox
Last Modified: 31-JUL-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 6.0 
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SYMPTOMS
========

When you type the command THISFORMSET.REMOVEOBJECT("FORM_NAME") to remove a form
from a formset, a message box with following message appears:

  Fatal error: Exception code = C0000005

After this message appears, Visual FoxPro terminates.

CAUSE
=====

This behavior occurs when a form is removed from a formset using the following
syntax:

  THISFORMSET.REMOVEOBJECT("FORM_NAME")

RESOLUTION
==========

The behavior does not occur if the form is released from the formset.

Use the following syntax to release a form that is part of a formset:

  THISFORM.RELEASE

STATUS
======

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

This bug was corrected in Visual Studio 6.0 Service Pack 3.

For more information about Visual Studio service packs, please see the following
articles in the Microsoft Knowledge Base:

  Q194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

  Q194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed

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

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

1. Close any open data files and exit any running applications.

2. Create a program file called RemFrm.prg using the following code:

  PUBLIC ox
  ox=CREATEOBJECT('testset')
  ox.SHOW

  DEFINE CLASS testset AS FORMSET
     ADD OBJECT form1 AS test1 WITH ;
        TOP    = 0, ;
        LEFT   = 0, ;
        HEIGHT = 250, ;
        WIDTH  = 375
  ENDDEFINE

  DEFINE CLASS test1 AS FORM
     DOCREATE = .T.
     CAPTION = "Form1"
     NAME = "Form1"

     ADD OBJECT command1 AS COMMANDBUTTON WITH ;
        TOP = 200, ;
        LEFT = 56, ;
        HEIGHT = 25, ;
        WIDTH = 241, ;
        CAPTION = "Add Form", ;
        NAME = "Command1"

     PROCEDURE command1.CLICK
        THISFORM.HIDE
        THISFORMSET.ADDOBJECT("Form2","test2")
        THISFORM.ENABLED=.F.
        THISFORMSET.FORMS[2].ENABLED=.T.
        THISFORMSET.FORMS[2].SHOW
     ENDPROC
  ENDDEFINE

  DEFINE CLASS test2 AS FORM
     TOP = 33
     LEFT = 140
     DOCREATE = .T.
     CAPTION = "Form2"
     VISIBLE = .F.
     NAME = "FORM2"
     AUTOCENTER=.T.

  ADD OBJECT command1 AS COMMANDBUTTON WITH ;
     TOP = 192, ;
     LEFT = 48, ;
     HEIGHT = 25, ;
     WIDTH = 241, ;
     CAPTION = "Remove Me", ;
     NAME = "Command1"

     PROCEDURE command1.CLICK
        THISFORM.HIDE
        THISFORMSET.FORMS[1].ENABLED=.T.
        THISFORMSET.FORMS[1].SHOW
        THISFORMSET.REMOVEOBJECT(THISFORM.NAME)
     ENDPROC
  ENDDEFINE

3. From the command prompt, type the following:

  DO REMFRM

4. Click Add Form.

5. Click Remove Me.

RESULT: A message box appears with the following error message:

  Fatal error: Exception code = C0000005

After clicking OK in the error message box, Visual FoxPro terminates.

(c) Microsoft Corporation 1999, All Rights Reserved.
Contributions by John Desch, Microsoft Corporation


Additional query words:

======================================================================
Keywords          : kbContainer kbCtrl kbvfp600 kbvfp600bug kbVS600sp3fix kbGrpDSFox 
Technology        : kbVFPsearch kbAudDeveloper kbVFP600
Version           : WINDOWS:6.0
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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