DOCUMENT:Q149341  11-SEP-2001  [visualc]
TITLE   :FIX: CreatePointFont() May Create Wrong Size Font in Preview
PRODUCT :Microsoft C Compiler
PROD/VER:winnt:4.0,4.1
OPER/SYS:
KEYWORDS:kbprint kbFont kbMFC kbPrinting kbVC400 kbVC410 kbDSupport kbGrpDSMFCATL kbNoUpdate

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

 - The Microsoft Foundation Classes (MFC), included with:
    - Microsoft Visual C++, 32-bit Editions, versions 4.0, 4.1 
-------------------------------------------------------------------------------

SYMPTOMS
========

Calling CFont::CreatePointFont() results in a font displayed in print preview
mode that is not of the point size requested.

CAUSE
=====

The CDC class contains two member variables for its current device context,
m_hDC and m_hAttribDC. m_hDC (the output device context) is equal to m_hAttribDC
(the attribute device context) by default. However, when print preview is
active, these two variables will not be equal; at that point, the m_hDC contains
the screen's device context and m_hAttribDC contains the printer's device
context.

The implementation of CreatePointFont() looks at the m_hDC member of the CDC
class to calculate the proper size for the font rather than the m_hAttribDC
member. The result of this behavior is that CreatePointFont will always create a
font sized for the screen device context.

RESOLUTION
==========

The following sample code works around the problem by creating another CDC
object based on the m_hAttribDC member of the original CDC and uses this new CDC
to call CFont::CreatePointFont().

Sample Code
-----------

   /* Compile options needed: default
   */ 

   void CMyView::OnDraw(CDC* pDC)
   {
       // dcPrinter's m_hDC and m_hAttribDC member variables
       // will both be properly pointing to the printer DC.
       CDC dcPrinter;
       dcPrinter.Attach(pDC->m_hAttribDC);

       CFont font;
       font.CreatePointFont(110, "Courier New", &dcPrinter);

       // You must detach from the DC after using
       // our temporary dcPrinter object or problems will occur!
       dcPrinter.Detach();

       CFont* pOldFont = pDC->SelectObject(&font);

       // Use font here...
       pDC->SelectObject(pOldFont);
   }

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 C++ 32- bit Edition
version 4.2.

Additional query words: 4.00 4.10 4.20 vcfixlist420

======================================================================
Keywords          : kbprint kbFont kbMFC kbPrinting kbVC400 kbVC410 kbDSupport kbGrpDSMFCATL kbNoUpdate 
Technology        : kbAudDeveloper kbMFC
Version           : winnt:4.0,4.1
Issue type        : kbbug
Solution Type     : kbfix

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

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