DOCUMENT:Q223103  24-JUL-2001  [vbwin]
TITLE   :FIX: Memory Leak with Command Button on Japanese Windows 95C
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:5.0,6.0
OPER/SYS:
KEYWORDS:kbservicepack kbFarEast kbIntl kbOSWin95OSR250 kbVBp kbVBp500bug kbVBp600bug kbOSWin95

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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
========

A memory leak might occur on Japanese Windows 95C (OSR 2.5) when unloading a
Form that contains a CommandButton.

CAUSE
=====

This problem occurs when the CommandButton's TabIndex property = "0" and its
TabStop property = "TRUE."

RESOLUTION
==========

Set the TabIndex of the CommandButton to a value greater than 0.

STATUS
======

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

This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information
about Visual Studio service packs, please see the following articles in the
Microsoft Knowledge Base:

Q194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

Q194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed

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

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

1. Start a new Visual Basic Standard EXE Project. Form1 is created by default.

2. Add a CommandButton and Timer control to Form1.

3. Add the following code to the General Declarations section of Form1:

   Option Explicit
   Private f As Boolean

   Private Sub Command1_Click()
      Timer1.Enabled = True
   End Sub

   Private Sub Form_Load()
      Timer1.Interval = 500
      Timer1.Enabled = False
   End Sub

   Private Sub Timer1_Timer()
      f = Not f
      If f Then
         Form2.Show
      Else
         Unload Form2
         Set Form2 = Nothing
      End If
   End Sub

4. On the Project menu, click Add Form to add a new form to the project. Form2
   is created by default.

5. Add a CommandButton to Form2.

6. Compile the Application to an EXE file.

7. Run the compiled EXE on Japanese Windows 95C.

8. Start the System Monitor tool, which is located in the System Tools folder in
   the Accessories folder. (If the System Monitor tool is not available, it can
   be installed from the Control Panel Add/Remove Programs option.) On the Edit
   menu, click Add Item. Click the Memory Manager Category, click the Allocated
   Memory Item, and click OK.

9. Click Command1 to start loading/unloading Form2.

   Result: The "Allocated Memory" will steadily increase as the application is
   running and might eventually cause the application to crash.

Additional query words:

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Keywords          : kbservicepack kbFarEast kbIntl kbOSWin95OSR250 kbVBp kbVBp500bug kbVBp600bug kbOSWin95 kbGrpDSVB kbVS600sp2 kbVS600SP1 kbVS600sp3fix kbIntlDev 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVB500 kbVB600
Version           : WINDOWS:5.0,6.0
Issue type        : kbbug
Solution Type     : kbfix

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Copyright Microsoft Corporation 2001.