FIX: Ambiguous Names Generate Incorrect Error Message

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

SYMPTOMS

If Binary Compatibility is set, then writing a duplicate Implements statement in a Class Module can cause a compatibility error to occur when compiling a DLL, instead of the expected "Ambiguous name detected" error message.

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

Steps to Reproduce Behavior

NOTE: MSO97.DLL is required to duplicate this scenario.

1. Start a new ActiveX DLL project in Visual Basic 5.0. Class1 is created by default.

2. Select Project...References from the menu bar and add a reference to the Microsoft Office 8.0 Object Library.

3. Select Project...Add Module to add a new Module (Module1).

4. Add the following code to Module1:

         Sub Main()
   
         End Sub
   
   

5. Add the following code to Class1:

         Implements IFoundFiles
   

         Private Property Get IFoundFiles_Count() As Long
   

         End Property
   

         Private Property Get IFoundFiles_Item(ByVal Index As Long) As String
   

         End Property
   

6. Select Project...Properties and change the Startup Object to Sub Main.

7. Select File...Make Project1.dll and compile the project as Project1.DLL.

8. After compilation, select Project...Project1 Properties, and select Binary Compatibility on the Components tab.

9. Change the code in Class1 to the following:

         Implements IFoundFiles
         Implements IFoundFiles
   

         Private Property Get IFoundFiles_Count() As Long
   

         End Property
   

         Private Property Get IFoundFiles_Item(ByVal Index As Long) As String
   

         End Property
   

10. Select File...Make Project1.dll, and compile the project as

        Project2.DLL.
    

Result

The following Visual Basic dialog box appears:

    "The Class1 class implemented an interface in the version-compatible
    component, but not in the current project.

   If you choose Accept, the Class1 class module will no longer support
   client applications compiled against the version-compatible component.
   To avoid this incompatibility, add the interface declaration back into
   the class module, or clear the version compatibility setting in Project
   Options."

   "Compile error: Ambiguous name detected: IFoundFiles"

NOTE: This behavior has also been reported when duplicate Enum names are used.

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