Q150764: PRB: CString::LoadString Fails in Console Application

Article: Q150764
Product(s): Microsoft C Compiler
Version(s): winnt:2.0,2.1,2.2,4.0,4.1
Operating System(s): 
Keyword(s): kbnokeyword kbMFC kbVC200 kbVC400 kbGrpDSMFCATL
Last Modified: 04-AUG-2001

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The information in this article applies to:

- The Microsoft Foundation Classes (MFC), used with:
   - Microsoft Visual C++, 32-bit Editions, versions 2.0, 2.1, 2.2, 4.0, 4.1 
-------------------------------------------------------------------------------

SYMPTOMS
========

CString::LoadString() generates an MFC assert in debug mode console applications
or fails in release mode console applications.

CAUSE
=====

CString::LoadString() relies on MFC global resource handles that are initialized
in AfxWinMain(), which is only called in MFC GUI-based applications.

RESOLUTION
==========

The resource string is loaded using the Win32 API ::LoadString() function. This
method does not require any extra MFC initialization.

Example #1 below uses this method.

It is possible to initialize the MFC global resource handles by calling the
undocumented AfxWinInit() function. In this case, it is advisable to declare an
instance of a CWinApp class.

Example #2 below demonstrates this method.


Sample Code - Example #1
------------------------

     /* Compile options needed: /MT
     */ 
     #include <afx.h>
     #include <stdio.h>
     #include <conio.h>

     #define IDS_HELLO 1

     BOOL LoadStringResource(CString &cszString, UINT nID)
     {
         int nSize = 0;
         int nLen = -1;

         cszString.Empty();

         //Keep looping until we have the whole string
         while ((nLen != 0) && (nLen == nSize - 1))
         {
             //Grow buffer by 256 bytes
             nSize += 256;

             //Load String Resource
             nLen = ::LoadString( GetModuleHandle(NULL), nID,
                                  cszString.GetBuffer(nSize-1), nSize);
         }
         cszString.ReleaseBuffer();

         return (BOOL) nLen;
     }

     void main(void)
     {
         AfxInitialize();

         CString cszString;

         // IDS_HELLO is a string resource attached to the console
     application
         if (LoadStringResource(cszString, IDS_HELLO))
             printf("The string was loaded\n%s\n", (LPCTSTR) cszString);
         else
             printf("Error loading string");

         getch();
     }

Sample Code - Example #2
------------------------

     /* Compile options needed: /MT
     */ 
     #include <afx.h>
     #include <afxwin.h>
     #include <conio.h>

     #define IDS_HELLO 1

     CWinApp theApp;

     void main()
     {
         if (!AfxWinInit(GetModuleHandle(NULL), NULL,
             ::GetCommandLine(), 0))
         {
             printf("Couldn't initialize MFC!\n");
             return;
         }

         CString cszString;

         // IDS_HELLO is a string resource attached to the console
     application
         if (cszString.LoadString(IDS_HELLO))
             printf("The string was loaded\n%s\n", (LPCTSTR) cszString);
         else
             printf("Error loading string");

         getch();
     }

STATUS
======

This behavior is by design.

Additional query words: 2.00 2.10 2.20 4.00 4.10

======================================================================
Keywords          : kbnokeyword kbMFC kbVC200 kbVC400 kbGrpDSMFCATL 
Technology        : kbAudDeveloper kbMFC
Version           : winnt:2.0,2.1,2.2,4.0,4.1
Issue type        : kbprb

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