DOCUMENT:Q171522  11-JAN-2001  [vbwin]
TITLE   :FIX: Enums in Public Procedures Cause Binary Compatibility Error
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:5.0
OPER/SYS:
KEYWORDS:kbVBp500 kbVS97sp2fix kbGrpDSVB kbvbp500sp2fix

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The information in this article applies to:

 - Microsoft Visual Basic Control Creation Edition for Windows, version 5.0 
 - Microsoft Visual Basic Learning Edition for Windows, version 5.0 
 - Microsoft Visual Basic Professional Edition for Windows, version 5.0 
 - Microsoft Visual Basic Enterprise Edition for Windows, version 5.0 
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SYMPTOMS
========

Using Enums as parameters/arguments in class module methods may result in binary
compatibility errors.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug has been fixed in Visual Studio 97 Service
Pack 2.

For more information on the Visual Studio 97 Service Pack 2, please see the
following article in the Microsoft Knowledge Base:

   Q170365 : INFO: Visual Studio 97 Service Packs - What, Where,and Why

For a list of the Visual Basic 5.0 bugs that were fixed in the Visual Studio 97
Service Pack 2, please see the following article in the Microsoft Knowledge
Base:

   Q171554 : INFO: Visual Basic 5.0 Fixes in Visual Studio 97 Service Pack 2

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

If you use Enum statements in class modules, they may cause adverse behavior to
your application when compiling and running if compatibility is set to "Binary
Compatibility." This seems to occur most frequently when enums are used as
parameters within a class's Method declaration in an ActiveX control or DLL.
Adverse behavior in your program may include "type mismatches" between arguments
and parameters even though they are correct. Compiler problems include Visual
Basic thinking the compatibility has been broken when it hasn't, and linker
errors during compilation.

To reproduce a compiling error (linker error):

1. Create a new ActiveX Control.

2. Add a new Class Module, and paste in the following code:

         Property Let Name(Effect As Stooge)
                  Msgbox "You Changed The Name"
         End Property

3. Add the following to the Control's General Declarations section:

         Public Enum Stooge
                Larry
                Curly
                Moe
         End Enum

4. Compile the Control.

5. Under Project -> Project Properties -> Components, change the
   compatibility to "Binary Compatibility."

6. Recompile the Control. You will get the following error message from the
   linker:

   "Unexpected error in code generator or linker - View error messages?"

Additional query words: kbDSupport

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Keywords          : kbVBp500 kbVS97sp2fix kbGrpDSVB kbvbp500sp2fix 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVBA500Search kbVBA500 kbVB500 kbZNotKeyword3
Version           : 5.0
Issue type        : kbbug
Solution Type     : kbfix

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Copyright Microsoft Corporation 2001.