Q156341: PRB: Cannot Load the Same Class Library More Than Once

Article: Q156341
Product(s): Microsoft FoxPro
Version(s): WINDOWS:5.0,6.0
Operating System(s): 
Keyword(s): kbvfp500 kbvfp600
Last Modified: 14-DEC-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 5.0, 6.0 
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SYMPTOMS
========

Visual FoxPro version 5.0 does not allow you to load the same class library more
than once, using the "SET CLASSLIB... ALIAS ... ADDITIVE" command.

WORKAROUND
==========

If you want to load the same class library multiple times, you have to create
multiple copies of the same class library in different directories and then load
each one. Following is an example to do so:

  SET CLASSLIB TO

  **Make a temp directory in the HOME() directory**
  MD HOME()+'temp'

  **Copy the Class Library files to the temp directory**
  COPY FILE HOME()+'wizards\wizstyle.vc?' to HOME()+'temp\wizstyle.vc?'

  **Load First instance of the Class Library**
  SET CLASSLIB TO HOME()+'wizards\wizstyle' ALIAS one

  **Display the Class Library(ies) Loaded into memory**
  ?SET('CLASSLIB')
  **The above command will display the First Library**

  **Load second instance of the Class Library
  SET CLASSLIB TO HOME()+'temp\wizstyle' ALIAS two ADDITIVE

  **Display the Class Library(ies) Loaded into memory**
  ?SET('CLASSLIB')
  **The above command will display both instances of the library**

STATUS
======

This behavior is by design.

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

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

The following steps demonstrate that, although the second instance of the Class
Library is opened using the ALIAS and ADDITIVE clause, the first instance of the
same class is closed, and only the second instance of the Class remains loaded
into memory:

1. Issue the following commands from the Command window:

       SET CLASSLIB TO HOME()+ "Wizards\Wizstyle" ALIAS One
       ?SET("Classlib")

     The ?SET("Classlib") command displays the following:

       ..\Vfp\Wizards\Wizstyle.vcx ALIAS One

2. Issue the following commands from the Command window:

       SET CLASSLIB TO HOME()+ "Wizards\Wizstyle" ALIAS Two ADDITIVE
       ?SET("Classlib")

     The ?SET("Classlib") command displays the following:

       ..\Vfp\Wizards\Wizstyle.vcx ALIAS Two

Additional query words: kbdse VFoxWin

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Keywords          : kbvfp500 kbvfp600 
Technology        : kbVFPsearch kbAudDeveloper kbVFP500 kbVFP600
Version           : WINDOWS:5.0,6.0

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