DOCUMENT:Q176429  11-JAN-2001  [vbwin]
TITLE   :BUG: Can't Check MDIChild Property of Forms in Forms Collection
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:
OPER/SYS:
KEYWORDS:kberrmsg kbnokeyword kbVBp500bug kbVBp600bug kbGrpDSVB

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The information in this article applies to:

 - Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0 
 - Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
 - Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
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SYMPTOMS
========

The following code worked in Visual Basic 4.0, but fails in Visual Basic 5.0 or
6.0 with an error "Error 380, Invalid Property Value" if an MDI parent form is
in the project:

      Dim f As Form
         For Each f In Forms
           If Not TypeOf f Is MDIForm Then
             If f.MDIChild Then
               Form1.Print f.Name & "   MDI Child"
             Else
               Form1.Print f.Name & "   Not MDI Child"
             End If
           Else
             Form1.Print f.Name & "  Not MDI Child"
           End If
         Next

CAUSE
=====

MDI forms do not have a MDIChild property in Visual Basic 4.0, 5.0, or 6.0.
Visual Basic 4.0 compensated for that in the specific case of looping through
the forms collection and checking this property, but Visual Basic 5.0 and 6.0 do
not.

RESOLUTION
==========

The workaround is to determine if the form is an MDI form before checking the
MDIChild property, which the following code demonstrates:

      Dim f As Form
      For Each f In Forms
        If Not TypeOf f Is MDIForm Then
          If f.MDIChild Then
            Form1.Print f.Name & "   MDI Child"
          Else
            Form1.Print f.Name & "   Not MDI Child"
          End If
        Else
          Form1.Print f.Name & "  Not MDI Child"
        End If
      Next

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.

Additional query words:

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Keywords          : kberrmsg kbnokeyword kbVBp500bug kbVBp600bug kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600
Issue type        : kbbug

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Copyright Microsoft Corporation 2001.