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Q145726: BUG: Setting FontTransparent Has No Effect on Windows 95/98/Me

Article: Q145726
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbprint kbPrinting kbVBp kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB kbDSupport
Last Modified: 07-SEP-2001

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The information in this article applies to:

- Microsoft Visual Basic Control Creation Edition for Windows, versions 5.0, 6.0 
- 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 
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SYMPTOMS
========

When printing under Windows 95, Windows 98, and Windows Me, the FontTransparent
property of the Printer object fails to change the way that the text is printed
on the background. The FontTransparent property determines whether background
text and graphics are displayed in the spaces around and within characters. The
Visual Basic default for this property is True, meaning that the background will
display in the spaces around the text. Under Windows 95, Windows 98, and Windows
Me, the text will print as if FontTransparent is set to False, even though it is
set to True.

Additionally, whenever a NewPage method is issued, all text on the new page will
print as if FontTransparent is set to False even if it was printing correctly on
the previous page.

CAUSE
=====

The background mix mode, which directly relates to the Visual Basic
FontTransparent property, and several other attributes of the printer device
context, are modified at the start of a page by Windows 95, Windows 98, and
Windows Me. This is a change in behavior from Windows NT and previous versions
of Windows that is not addressed properly by the Visual Basic Printer Object.
The problem should only affect the 32-bit version of Visual Basic, although some
cases of the 16-bit version exhibiting this behavior have been reported. For
more information on the cause, please see the following article in the Microsoft
Windows SDK Knowledge Base:

  Q125696 : StartPage/EndPage Resets Printer DC Attributes in Windows 95

RESOLUTION
==========

To work around the problem, call the SetBKMode Windows API function to set the
background mix mode. An example is shown in the More Information section below.

STATUS
======

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

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

This problem is printer driver-specific, meaning that the exact symptoms can
vary from driver to driver. Some drivers do not experience this problem at all,
while others reset the background mix mode to Opaque when any Printer object
property is changed. This article describes the most common scenario. To make
sure that you cover the worst possible case, you should call the SetBkMode
function just before your Printer.Print calls. Then if you change any property
of the Printer object, call SetBkMode again.

The code to duplicate the problem is as follows:

1. Start Visual Basic. From the File menu, choose New Project (ALT, F, N). Form1
  is created by default.

2. In the click event of the form, add the following code:

     Private Sub Form_Click()

        Printer.Line (0,0)-(10000, 2000), &HC0C0C0, BF
        Printer.CurrentX = 0
        Printer.CurrentY = 0
        Printer.FontTransparent = True
        Printer.Print "Printer.FontTransparent = " & Printer.FontTransparent
        Printer.FontTransparent = False
        Printer.Print "Printer.FontTransparent = " & Printer.FontTransparent
        Printer.EndDoc

     End Sub

3. From the Run menu, choose start (ALT, R, S), or press the F5 key to run the
  program.

4. Click the form. The result should be a gray page with one line of black text
  in the upper left corner and another line of black text in a white box
  beneath the first. On Windows 95, Windows 98, and Windows Me, this will yield
  a gray page with a white box and black text for both lines.

The following steps correct the problem in the previous example:

1. Add the following declarations to the General section of the form:

     #If Win32 Then

        Private Declare Function SetBkMode Lib "gdi32"  _
        (ByVal hdc As Long, ByVal nBkMode As Long) As Long

        Private iBKMode as Long

     #Else

        Private Declare Function SetBkMode Lib "GDI" (ByVal hDC As Integer _
         , ByVal nBkMode As Integer) As Integer

        Private iBKMode as Integer

     #End If

        Private Const TRANSPARENT = 1
        Private Const OPAQUE = 2

2. Correct the code in the click event of the form as such:

      Private Sub Form_Click()

         Printer.Print ""
         Printer.Line (0,0)-(10000, 2000), &HC0C0C0, BF
         Printer.CurrentX = 0
         Printer.CurrentY = 0
         Printer.FontTransparent = True
         'Correctly sets the background mix mode to transparent
         iBKMode = SetBKMode(Printer.Hdc, TRANSPARENT)
         Printer.Print "Printer.FontTransparent = " & Printer.FontTransparent
         Printer.FontTransparent = False
         'Correctly sets the background mix mode to opaque
         iBKMode = SetBKMode(Printer.Hdc, OPAQUE)
         Printer.Print "Printer.FontTransparent = " & Printer.FontTransparent
         Printer.EndDoc

      End Sub

3. From the Run menu, choose start (ALT, R, S), or press the F5 key to run the
  program.

4. Click the form. The text should now print as expected.

REFERENCES
==========

For additional information, click the article number below to view the article
in the Microsoft Knowledge Base:

  Q183163 BUG: Setting Orientation Changes Background Mix Mode for Printer

Additional query words:

======================================================================
Keywords          : kbprint kbPrinting kbVBp kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB kbDSupport 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500Search kbVB500 kbVB600 kbVB400Search kbVB400 kbZNotKeyword3 kbVB16bitSearch
Version           : :4.0,5.0,6.0
Issue type        : kbbug
Solution Type     : kbpending

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