Q200440: PRB: MFC SAVER Sample Does Not Run Correctly

Article: Q200440
Product(s): Microsoft C Compiler
Version(s): 5.0,6.0
Operating System(s): 
Keyword(s): kbMFC kbScreenSaver kbVC500 kbVC600 kbOSWin98 kbSamplePro kbGrpDSMFCATL
Last Modified: 07-MAY-2001

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The information in this article applies to:

- Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0 
- Microsoft Visual C++, 32-bit Professional Edition, versions 5.0, 6.0 
- Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
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SYMPTOMS
========

When you configure the MFC SAVER sample in Control Panel, it does not run
correctly. When you click Settings for the screen saver, nothing happens.

CAUSE
=====

The problem is caused by a coding error in the MFC sample. The MatchOption()
function performs a string comparison instead of a character comparison.

RESOLUTION
==========

To resolve this problem so you can configure the screen saver in the Control
Panel, change the existing MatchOption() and InitInstance() functions as
follows:

  BOOL MatchOption(LPTSTR lpsz, TCHAR ch)
  {
      if (lpsz[0] == '-' || lpsz[0] == '/')
          lpsz++;

      if (lpsz[0] == ch)
          return TRUE;

      return FALSE;
  }

  ///////////////////////////////////////////////////////////////////////////// 
  // CSaverApp initialization.
  BOOL CSaverApp::InitInstance()
  {
      // Standard initialization.
      // If you are not using these features and want to reduce the size
      // of your final executable, you should remove from the following
      // the specific initialization routines you do not need.

      Enable3dControls();
      SetRegistryKey(_T("MFC Screen Savers Inc."));

      if (__argc == 1 || MatchOption(__argv[1], _T('c')))
          DoConfig();

      else if (MatchOption(__argv[1], _T('p')))
      {
          CWnd* pParent = CWnd::FromHandle((HWND)atol(__argv[2]));
          ASSERT(pParent != NULL);
          CDrawWnd* pWnd = new CDrawWnd();
          CRect rect;
          pParent->GetClientRect(&rect);
          pWnd->Create(NULL, WS_VISIBLE|WS_CHILD, rect, pParent, NULL);
          m_pMainWnd = pWnd;
          return TRUE;
      }
      else if (MatchOption(__argv[1], _T('s')))
      {
          CSaverWnd* pWnd = new CSaverWnd;
          pWnd->Create();
          m_pMainWnd = pWnd;
          return TRUE;
      }

      return FALSE;
  }

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

Steps to Reproduce Behavior
---------------------------

  BOOL MatchOption(LPTSTR lpsz, LPTSTR lpszOption)
  {
      if (lpsz[0] == '-' || lpsz[0] == '/')
          lpsz++;

      if (lstrcmpi(lpsz, lpszOption) == 0) // 
          return TRUE;

      return FALSE;
  }

  ///////////////////////////////////////////////////////////////////////////// 
  // CSaverApp initialization.
  BOOL CSaverApp::InitInstance()
  {
    // Standard initialization.
    // If you are not using these features and you want to reduce the size
    // of your final executable, you should remove from the following
    // the specific initialization routines you do not need.
      Enable3dControls();
      SetRegistryKey(_T("MFC Screen Savers Inc."));

      if (__argc == 1 || MatchOption(__argv[1], _T("c")))
          DoConfig();

      else if (MatchOption(__argv[1], _T("p")))
      {
          CWnd* pParent = CWnd::FromHandle((HWND)atol(__argv[2]));
          ASSERT(pParent != NULL);
          CDrawWnd* pWnd = new CDrawWnd();
          CRect rect;
          pParent->GetClientRect(&rect);
          pWnd->Create(NULL, WS_VISIBLE|WS_CHILD, rect, pParent, NULL);
          m_pMainWnd = pWnd;
          return TRUE;
      }
      else if (MatchOption(__argv[1], _T("s")))
      {
          CSaverWnd* pWnd = new CSaverWnd;
          pWnd->Create();
          m_pMainWnd = pWnd;
          return TRUE;
      }

      return FALSE;
  }

REFERENCES
==========

Visual C++ Help for SAVER sample

(c) Microsoft Corporation 1999, All Rights Reserved. Contributions by Nathan
Manis, Microsoft Corporation.


Additional query words:

======================================================================
Keywords          : kbMFC kbScreenSaver kbVC500 kbVC600 kbOSWin98 kbSamplePro kbGrpDSMFCATL 
Technology        : kbVCsearch kbAudDeveloper kbVC500 kbVC600 kbVC32bitSearch kbVC500Search
Version           : :5.0,6.0
Issue type        : kbprb

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