Q158755

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page	Q158755: FIX: CLEAR ALL with Object References Causes Page Fault	/kb/158/Q158755/

Q158755: FIX: CLEAR ALL with Object References Causes Page Fault

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Article: Q158755
Product(s): Microsoft FoxPro
Version(s): WINDOWS:5.0
Operating System(s): 
Keyword(s): kberrmsg
Last Modified: 24-MAR-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 5.0 
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SYMPTOMS
========

If there are objects that reference each other, Visual FoxPro displays the
following error message when CLEAR ALL is carried out:

  This Program has performed an illegal operation and will be shut down.

Visual FoxPro terminates due to an Invalid Page Fault.

WORKAROUND
==========

Delete object references before carrying out CLEAR ALL.

STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products listed at
the beginning of this article. This has been corrected in Visual FoxPro 6.0.

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

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

1. Create and run a program containing the following code:

        oform = CreateObject( "Form" )
        oform.AddObject("X", "CB")
        oform.AddObject("Y", "CB")
        oform.y.pointer=oform.x
        oform.x.pointer=oform.y
        CLEAR ALL  && This causes an Invalid Page Fault and
                   && shuts down Visual FoxPro.

        DEFINE CLASS CB as CommandButton
          pointer= .NULL.
        ENDDEFINE

Object references for "X" and "Y" above can be cleared by doing the following:

        oform.removeobject("X")
        oform.removeobject("Y")

Additional query words: vfoxwin kbdsd kbvfp500 kbvfp600fix

======================================================================
Keywords          : kberrmsg 
Technology        : kbVFPsearch kbAudDeveloper kbVFP500
Version           : WINDOWS:5.0
Issue type        : kbbug
Solution Type     : kbfix

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