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Q79242: BUG: Some Property Values May Be Incorrect in Maximized Form

Article: Q79242
Product(s): Microsoft Visual Basic for Windows
Version(s): 1.0,2.0,3.0,3.1
Operating System(s): 
Keyword(s): 
Last Modified: 02-NOV-2001

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The information in this article applies to:

- Microsoft Visual Basic Professional Edition for Windows, versions 2.0, 3.0 
- Microsoft Visual Basic Standard Edition for Windows, versions 1.0, 2.0, 3.0 
- Microsoft Windows versions 3.0, 3.1 
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SYMPTOMS
========

The Top, Left, ScaleHeight, and ScaleWidth properties of a maximized Visual
Basic for Windows form may return incorrect values. When a form is maximized,
the values returned by these properties should be close to the resolution of
your monitor. The only difference between the property values returned and the
resolution should be due to BorderStyles, menus, or title bars, and should in no
case be greater than the resolution of your monitor.

CAUSE
=====

In some cases, with a maximized form, the returned property values can be
greater than the screen resolution. This is because of a problem in the Windows
API routine, GetClientRect(), which Visual Basic calls to get the form
properties. This is a problem with Microsoft Windows versions 3.0 and 3.1, not
with Visual Basic.

STATUS
======

Microsoft has confirmed this to be a bug in Microsoft Windows versions 3.0 and
3.1. We are researching this problem and will post new information here in the
Microsoft Knowledge Base as it becomes available.

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

The Left property determines the distance between the internal left edge of an
object and the left edge of its container. The Top property determines the
distance between the internal top edge of an object and the top edge of its
container. ScaleHeight sets or returns the range of the vertical axis for an
object's internal coordinate system, and ScaleWidth sets or returns the
horizontal axis. On a form, the coordinate system includes the form's internal
area, not including borders and title bar.

Steps to Reproduce Problem
--------------------------

To duplicate the problem, experiment with various BorderStyles, set ScaleMode to
pixels, and add the following code:

     Sub Form_Click()
        Print Left,Top,ScaleWidth,ScaleHeight
     End Sub

Run the application and click the form. Note the values printed. With no border,
the values should correspond to the resolution of your monitor, and should
change slightly for each BorderStyle from the addition of borders, menus, and
title bars.

Here's another example. This occurs when you use the following code in a
maximized form with a ScaleMode of 1 (twips) in a 800-by-600 (pixel) screen
resolution:

     Sub Form_Click
        Print "Screen = "; screen.width; ", "; screen.height
        ' Enter each Print statements on one, single line.
        Print "Form = "; form1.width; ", "; form1.height;
                      " at "; form1.left; ", "; form1.top
        Print "-------------------------------------------------------
               ------------------------"
     End Sub

The following is the results:

  Screen = 12000, 9000
  Form = 12120, 9120 at -60, -60

Additional query words: buglist3.00 buglist3.10 2.00 3.00 3.10

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Keywords          :  
Technology        : kbVBSearch kbAudDeveloper kbWin3xSearch kbZNotKeyword6 kbZNotKeyword2 kbVB300Search kbVB300 kbZNotKeyword3 kbWin300 kbWin310 kbVB200
Version           : :1.0,2.0,3.0,3.1
Issue type        : kbbug

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