WD2000: Converted WordBasic On Error Statements May Fail

ID: Q202019

The information in this article applies to:

SYMPTOMS

When you run a Microsoft Visual Basic for Applications procedure or macro that was converted from a WordBasic procedure or macro that contained error trapping, the error trap is ignored, although it worked as expected when run in WordBasic.


CAUSE

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http://www.microsoft.com/mcsp/
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http://www.microsoft.com/support/supportnet/refguide/



By design, the On Error statement in Visual Basic for Applications works differently from the way it does in WordBasic. In Visual Basic for Applications, On Error is not cleared when an error occurs. In WordBasic, the On Error statement is cleared, the error trap is reset, and your code continues to run.

Therefore, the following sample converted WordBasic code fails when an error occurs the second time. 


Sub Main()
   ' Clear error trap. Set error trap.
   On Error GoTo -1: On Error GoTo ErrorTrap
   ' Loop 10 times.
   For i = 1 To 10
      ' Artificially raise an error.
      Err.Raise 5
ErrorTrap:
     ' Decision tree based on error returned.
     If Err.Number = 0 Then
         ' If no error occurred, do this...
         count_ = count_ + 1
     Else
         ' Else, if error occurred, do this...
         Err.Number = 0
     End If
   Next
End Sub


WORKAROUND

To work around this issue, make the On Error statement the first statement inside the loop. 



Sub Main()
   ' Loop 10 times.
   For i = 1 To 10
   ' Clear error trap. Set error trap.
   On Error GoTo -1: On Error GoTo ErrorTrap
      ' Artificially raise an error.
      Err.Raise 5
ErrorTrap:
     ' Decision tree based on error returned.
     If Err.Number = 0 Then
         ' If no error occurred, do this...
         count_ = count_ + 1
     Else
         ' Else if error occurred, do this...
         Err.Number = 0
     End If
   Next
End Sub


In this example, the Err.Raise statement artificially raises an error for demonstration purposes. When the error occurs and the next iteration of the loop occurs, the On Error GoTo -1 statement clears the error trap and the On Error GoTo ErrorTrap statement resets the error trap. The loop continues to process without interruption until it completes the designated number of iterations (10).


STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.


REFERENCES

For more information about on error statement, in the Visual Basic Editor, click Microsoft Visual Basic Help on the Help menu, type "on error" in the Office Assistant or the Answer Wizard, and then click Search to view the topic.

For more information about getting help with Visual Basic for Applications, please see the following article in the Microsoft Knowledge Base:

Q226118 OFF2000: Programming Resources for Visual Basic for Applications

Additional query words: vba 


Keywords          : kbprg kbdta OffVBA kbmacroexample word8 kbwordvba word97 wd2000 
Version           : WINDOWS:2000
Platform          : WINDOWS 
Issue type        : kbbug

Last Reviewed: June 15, 1999