DOCUMENT:Q190220  07-AUG-1998  [vbwin]
TITLE   :PRB: "Invalid Property Value" When You Query MDIChild Property
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:5.0
OPER/SYS:WINDOWS
KEYWORDS:kbVBp500 kbVBp600 kbcode kberrmsg kbnokeyword

======================================================================
---------------------------------------------------------------------
The information in this article applies to:

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

SYMPTOMS
========

In Visual Basic, if you query for the MDIChild property of an MDI Parent
form, the following error occurs:

   Error 380 : Invalid Property Value

CAUSE
=====

MDI Parent forms do not have an MDIChild property. To query for this
nonexistent property will result in the above error.

RESOLUTION
==========

To resolve this, use the following code to query for the MDIChild property
of a form:

Sample Code
-----------

   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
======

This behavior is by design.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

1. Create a new Standard EXE project in Visual Basic.

2. Add an MDI form to the project by selecting Add MDI Form from the
   Project menu.

3. Set the MDIChild property of Form1 to True.

4. Paste the following code in the General Declarations section of Form1:

      Private Sub Form_Click()
         Dim f As Form
         For Each f In Forms
            If f.MDIChild Then
               Form1.Print f.Name & "   MDI Child"
            Else
               Form1.Print f.Name & "   Not MDI Child"
            End If
         Next
      End Sub

5. Press F5 to run the project

6. Click on Form1.

An error message displays "Run-Time Error 380 : Invalid Property Value"
instead of printing all of the names of the forms, and a value indicating
whether or not they are an MDI Child form

Additional query words:
======================================================================
Keywords          : kbVBp500 kbVBp600 kbcode kberrmsg kbnokeyword
Version           : WINDOWS:5.0
Platform          : WINDOWS
Issue type        : kbprb

=============================================================================

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