BUG: New Implements Does Not Generate Incompatibility Error (190492)


The information in this article applies to:

  • Microsoft Visual Basic Learning Edition for Windows 6.0
  • Microsoft Visual Basic Professional Edition for Windows 6.0
  • Microsoft Visual Basic Enterprise Edition for Windows 6.0
This article was previously published under Q190492

SYMPTOMS

If you remove a Public data member and add an Implements statement with the same class name as the removed Public data member and with Binary Compatibility set, Visual Basic does not generate a compatibility error as expected.

Existing client applications using the data member may generate a fatal error (GPF) with the new compatible server.

RESOLUTION

If you comment out Public data members, ensure you are not using the same identifier name in an Implements statement.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

  1. Create a new ActiveX DLL project in Visual Basic. Class1 will be created by default.
  2. Set the Instancing Property of Class1 to 2-PublicNotCreateable.
  3. Add a Class to the project by selecting Add Class Module from the Project menu.
  4. Add the following code to Class1: 
          Public Class2 As Class2
  5. Add the following code to Class2: 
          Public Class1 As Class1
  6. From the File Menu, click on Make Project1 to compile the Project and make Project1.dll
  7. From the Project Menu, select Project1 Properties.
  8. Select the Component tab, check the Binary Compatibility Radio Button, and then click OK to set Binary Compatibility.
  9. Comment out the data member in Class2 as shown below: 
          ' Public Class1 As Class1
  10. In Class2, paste the following code: 
          Implements Class1
      Private Property Set Class1_Class2(ByVal RHS As Class2)

      End Property

      Private Property Get Class1_Class2() As Class2

      End Property
  11. Recompile the project, and make the Project1.Dll. Note that the ActiveX DLL compiles as expected. However, a compatibility error should have been raised.
Modification Type:MajorLast Reviewed:5/13/2003
Keywords:kbbug KB190492
©2002 Microsoft Corporation. All rights reserved.