PRB: Setting the Optional Byte Argument Default Value to TRUE Breaks Binary Compatibility

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0

SYMPTOMS

Setting the default value of an Optional Byte argument to TRUE causes the following error when the project is compiled with Binary Compatibility:

<procedure> in the <class> class module has arguments and/or a return type that is incompatible with a similar declaration in the version-compatible component

RESOLUTION

Use 255 instead of TRUE for the default value.

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a new ActiveX DLL project.



2. Insert the following code into Class1:




Option Explicit

Public Function meth1(pf1 As String, Optional pf2 As Byte = True) As Boolean
' Sample method
End Function 

3. From the File menu, select Make Project1.DLL.



4. From the Project menu, select Project1 Properties.



5. Click on the Component tab.



6. Set the Version Compatibility to Binary Compatibility.



7. Verify that Project1.dll is listed in the File Location box at the bottom of the form.



8. Close the Project Properties dialog box.



9. Select Make Project1.dll from the File menu. Change the path to the DLL so that it is in a different location than the originally-compiled version of project1.dll and click OK. The error occurs at this point.

REFERENCES

For additional information about a similar problem with optional String argument default value, please click the article number below to view it in the Microsoft Knowledge Base:

Q176164 FIX: Optional Argument Default Value Breaks Binary Compatibility

Additional query words:

Keywords : kbVBp kbVBp500bug kbVBp600bug kbGrpVB kbDSupport
Version : WINDOWS:5.0,6.0
Platform : WINDOWS
Issue type : kbprb