BUG: Some Property Values May Be Incorrect in Maximized Form

- Standard and Professional Editions of Microsoft Visual Basic for

  Windows, versions 2.0 and 3.0

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

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

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