DOCUMENT:Q231689  11-JAN-2001  [vbwin]
TITLE   :BUG: Moving Controls on a Form Triggers Form_MouseMove Event
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:6.0
OPER/SYS:
KEYWORDS:kbActivexEvents kbVBp kbVBp600bug kbGrpDSVB kbDSupport

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

 - Microsoft Visual Basic Learning Edition for Windows, version 6.0 
 - Microsoft Visual Basic Professional Edition for Windows, version 6.0 
 - Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

When you move controls on a form and the cursor is over the form, the form's
MouseMove event gets triggered even if the cursor is not moving.

RESOLUTION
==========

In this scenario, if you need to place code in the form's MouseMove event and
want to be sure it runs only when the mouse is actually moving, you will need to
set a flag before moving any control on the form. Check the flag in the
MouseMove event before executing any code.

STATUS
======

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

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

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

1. Start a new Standard EXE project. Form1 is created by default.

2. Add a PictureBox control (Picture1) to Form1.

3. Add a TextBox control (Text1) to Form1. Make it high enough to display
   multiple lines and set the Multiline property to True.

4. Place three CommandButtons on the form. Name them as below and set the
   captions accordingly:

   cmdMove       &Move
   cmdStart      &Start Log
   cmdStop       &End Log

5. Add the following code to the module of Form1:

   Option Explicit
   Dim iLog As Long

   Private Sub cmdMove_Click()
       Dim l As Integer, t As Integer
       l = Picture1.Left + Picture1.Width / 2
       t = Picture1.Top
       Picture1.Move l, t
   End Sub

   Private Sub cmdStart_Click()
       Text1.Text = ""
       iLog = 1
   End Sub

   Private Sub cmdStop_Click()
       iLog = 0
   End Sub

   Private Sub Form_Load()
       iLog = 0
   End Sub

   Private Sub Form_MouseMove(Button As Integer, Shift As Integer, _
      x As Single, y As Single)
       If iLog = 1 Then Text1.Text = Text1.Text & "Form " & x & _
          " " & y & " " & Date & vbCrLf
   End Sub

6. Save the project.

7. Press F5 to run the project.

8. Place the mouse over the form.

9. You can move Picture1 by using Alt+M.

10. You can start logging MouseMove events by using Alt+S.

11. Start logging and move Picture1. Every time you move the picture, a
   MouseMove event gets logged in the TextBox. Note that this only happens if
   the mouse is over the form.

Additional query words:

======================================================================
Keywords          : kbActivexEvents kbVBp kbVBp600bug kbGrpDSVB kbDSupport 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVBA600 kbVB600
Version           : WINDOWS:6.0
Issue type        : kbbug
Solution Type     : kbpending

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

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 2001.