FIX: Enums in Public Procedures Cause Binary Compatibility Error

• Microsoft Visual Basic Control Creation, Learning, Professional, and Enterprise Editions for Windows, version 5.0

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:

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

   ARTICLE-ID: Q171554
   TITLE     : 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?"

Keywords          : vb5all VS97FixlistSP3 VS97FixlistSP2 VB5FixlistSP2
Version           : 5.0
Platform          : WINDOWS
Issue type        : kbbug
Solution Type     : kbfix kbservicepack