Microsoft KB Archive/171819

= FIX: Invalid Enum Value Causes Incompatible Binary Compatible =

Article ID: 171819

Article Last Modified on 12/10/2003

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APPLIES TO


 * Microsoft Visual Basic 5.0 Control Creation Edition
 * Microsoft Visual Basic 5.0 Learning Edition
 * Microsoft Visual Basic 5.0 Professional Edition
 * Microsoft Visual Basic 5.0 Enterprise Edition

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This article was previously published under Q171819



SYMPTOMS
Incompatibility Warnings may appear when you are trying to make a project with binary compatibility even though no subroutine or function declaration has changed.



CAUSE
If a function declaration contains an optional parameter with a default value in the declaration that does not use a valid enum, Visual Basic will define it as a short, which conflicts with the compiled version which is a long.



RESOLUTION
Install Visual Studio 97 Service Pack 2 or use a valid enumeration in the Function or Subroutine declaration.



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:

170365 : INFO: Visual Studio 97 Service Packs - What, Where, and Why

For a list of the Visual Basic 5.0 bugs that were fixed in the Visual Studio 97 Service Pack 2, please see the following article in the Microsoft Knowledge Base:

171554 : INFO: Visual Basic 5.0 Fixes in Visual Studio 97 Service Pack 2



MORE INFORMATION
This will only affect optional default parameters that do not use valid enumerations when setting the parameter to a default value.

Steps to Reproduce Behavior
 Start a New ActiveX EXE in Visual Basic 5.0.  In the General Declarations section of Class1, place the following code: Public sub food( Optional x as DrawModeConstants = 1) End Sub

 Select Project1 properties from the Project menu. Select the Component Tab and then make sure that the Project Compatibility button is selected. Click OK. Select Make Project1.exe from the File Menu. Click OK.</li> Select Project1 Properties from the Project menu.</li> Select the Component Tab and then make sure that Binary Compatibility is selected with the /project1.exe file you recently created showing in the text box. Click OK.</li> Select Make Project1.exe from the File Menu. Click OK.</li></ol>

You will now get a dialog box that warns of incompatibilities in the declaration of the version-compatible component. This should not be occurring because you have not modified the subroutine declaration. If you continue and select "Accept," you will get another message that recommends canceling the operation.

As a workaround, if the declaration above used a valid enumeration such as the following, the error would not occur:

Public Sub food( Optional x as DrawModeConstanst = vbBlackness) End Sub

Additional query words: kbDSupport

Keywords: kbbug kbfix kbvbp500sp2fix kbvs97sp2fix KB171819

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