WD98: Converted WordBasic On Error Statements May Fail (181064)
The information in this article applies to:
- Microsoft Word 98 Macintosh Edition
This article was previously published under Q181064 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 though it worked as expected when run
in WordBasic.
CAUSEMicrosoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements.
By design, the On Error statement in Visual Basic works differently from
WordBasic. In Visual Basic, On Error is not cleared when an error occurs,
while 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
RESOLUTION
To resolve 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. We are researching this problem
and will post new information here in the Microsoft Knowledge Base as it
becomes available.
REFERENCES
For more information about the On Error Statement, click the Office
Assistant in the Visual Basic Editor, type On Error, click Search, and
then click to view "On Error Statement."
NOTE: If the Assistant is hidden, click the Office Assistant button on the
Standard toolbar. If Word Help is not installed on your computer, please
see the following article in the Microsoft Knowledge Base:
179216 OFF98: How to Use the Microsoft Office Installer Program
For more information about getting help with Visual Basic for Applications,
please see the following article in the Microsoft Knowledge Base:
163435 VBA: Programming Resources for Visual Basic for Applications
| Modification Type: | Major | Last Reviewed: | 6/17/2005 |
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| Keywords: | kbbug kbdtacode kbnofix KB181064 |
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