FIX: Removing Function Causes Binary Compatibility Error

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

SYMPTOMS

If you recompile an ActiveX DLL with binary compatibility after changing the interface, Visual Basic will not always warn you. However, this action will result in an incompatible interface.

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

Changing the interface to an ActiveX DLL (such as changing the arguments in a function or removing a function) should result in Visual Basic warning you of the change when you try to compile the new DLL. However, this may not happen.

Steps to Reproduce Behavior

1. Start a new ActiveX DLL in Visual Basic 5.0.

2. Cut and paste the following code to the Class1 Class Module:

          Public Enum Test
            Larry
            Curly
            Moe
          End Enum
   
          Public Sub Test()
            ' This comment is so this sub compiles
          End Sub
   
   

3. Under the Project | Project Properties | Component menu, make sure the project's version compatibility is set to "Project Compatibility." (It should default to this setting.)

4. Compile Project1.DLL.

5. Comment out the Test Sub.

6. Under the Projects | Properties | Component menu, switch the projects version compatibility to "Binary Compatibility." Make sure the compatible version file is Project1. (This is the default setting.)

7. Compile Project1 again. This time, save the filename as Project2. Visual Basic will compile the DLL without any complaints although it should raise a 'broken compatibility' warning dialog box.

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