DOCUMENT:Q108706  27-JUL-2001  [visualc]
TITLE   :Common Q&A for Visual C++ 32-bit edition, ver 1.0
PRODUCT :Microsoft C Compiler
PROD/VER:1.00
OPER/SYS:
KEYWORDS:kbGenInfo kbVC kbArtTypeINF

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The information in this article applies to:

 - Microsoft Visual C++, version 1.0 
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SUMMARY
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Common Q&A for Microsoft Visual C++, 32-Bit Edition
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You can find the answers to more common questions by choosing "Technical Support"
from the Help menu in the Visual Workbench. The README.WRI file, located in the
\MSVCNT\HELP directory, also addresses many common issues.

1. Q. When I build my application, I get the warning, "LNK4016: unresolved
   external symbol `__doserrno'". What is causing this warning?

   A. The most likely cause of this error is using /MT (multithreaded run time)
   or /MD [run time in a DLL (dynamic-link library)] when building your
   application and linking with the supplied versions of the Microsoft
   Foundation Class (MFC) Libraries. To resolve this problem, you must rebuild
   the MFC libraries to use the same version of the run-time library as your
   application. Please see the README.WRI file located in \MSVCNT\HELP for more
   details.

2. Q. Can I use the Microsoft Foundation Class (MFC) Libraries in a
   multithreaded program?

   A. Yes. However, all use of the Microsoft Foundation Classes must be in the
   same thread. Please see TechNote #37 for more detailed information.

3. Q. I copied a sample project from the Visual C++ CD to my hard drive. Visual
   C++ is treating the sample as a read-only project. What's wrong?

   A. When files are copied from a CD to a hard drive, the files are given the
   read-only attribute. You can change the attribute by using the ATTRIB command
   in MS-DOS, or by choosing Properties from the File menu in the File Manager.
   Note that if you change the attribute of the file, you should also change the
   attribute of its directory.

4. Q. Where is the MFC200.DLL file located?

   A. MFC 2.0 does not support AFXDLLs (MFC in a DLL and extension DLLs) in this
   version of the Visual C++ development system for Windows NT. For more
   information, see the "Microsoft Foundation Class Library Update" at the
   beginning of the Class Library Reference.

5. Q. Can I use .VBX controls with App Studio and MFC 2.0?

   A. .VBX controls are 16-bit DLLs and are not supported in the 32-bit Visual
   C++ environment.

6. Q. I rebuilt my program with the 32-bit version of Visual C++, but now I get
   heap errors when I run my program. What is wrong?

   A. If you were using the Win32 Software Development Kit (SDK) before, it's
   very possible that you were writing past the memory block and not being
   caught. The Win32 SDK run-time libraries often allocate more space than is
   requested. The Visual C++ run time is more strict with heap allocations.

7. Q. In Windows 3.1, I could send my diagnostic output (OutputDebugString
   messages and MFC TRACE output) to the communications (com) port or my
   monochrome monitor. How do I do that in the Visual C++ development system for
   Windows NT?

   A. Under Windows NT, debug output is available only to the debugger of the
   process that issues the message. If you want to see the debug output of a
   program, run it under Visual Workbench integrated debugger or use the DEB
   (Debug Event Browser) sample in MSVCNT\SAMPLES\DEB.

Additional query words: kbinf 1.00
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Keywords          : kbGenInfo kbVC kbArtTypeINF 
Technology        : kbVCsearch kbAudDeveloper kbvc100
Version           : 1.00

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