简单看AfxOleInit()的内部工作~~

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_AFX_THREAD_STATE* pState = AfxGetThreadState();
ASSERT(!pState->m_bNeedTerm); // calling it twice?

if (afxContextIsDLL)
{
pState->m_bNeedTerm = -1; // -1 is a special flag
return TRUE;
}

// first, initialize OLE
SCODE sc = ::OleInitialize(NULL);
if (FAILED(sc))
{
  // warn about non-NULL success codes
#ifdef _DEBUG
  TRACE(traceOle, 0, _T("Warning: OleInitialize returned scode = %s.\n"),
   AfxGetFullScodeString(sc));
#endif
  goto InitFailed;
}
// termination required when OleInitialize does not fail
pState->m_bNeedTerm = TRUE;

// hook idle time and exit time for required OLE cleanup
CWinThread* pThread; pThread = AfxGetThread();
ASSERT(pThread);
pThread->m_lpfnOleTermOrFreeLib = AfxOleTermOrFreeLib;

// allocate and initialize default message filter
if (pThread->m_pMessageFilter == NULL)
{
  pThread->m_pMessageFilter = new COleMessageFilter;
  ASSERT(AfxOleGetMessageFilter() != NULL);
  AfxOleGetMessageFilter()->Register();
}
return TRUE;

InitFailed:
AfxOleTerm();
return FALSE;

上面有两个东西：

API OleInitialize初始化Ole库，实质--OleInitialize calls CoInitializeEx internally to initialize the COM library on the current apartment. Because OLE operations are not thread-safe, OleInitialize specifies the concurrency model as single-thread apartment.

pThread->m_lpfnOleTermOrFreeLib = AfxOleTermOrFreeLib;设置释放的回调函数。

if (bTerm)
{
  AfxOleTerm(bJustRevoke);
}
else
{
  // initialize _afxTickCount if necessary
  if (!_afxTickInit)
  {
   _afxTickCount = ::GetTickCount();
   ++_afxTickInit;
  }

  // only call CoFreeUnusedLibraries if one minute has gone by
  if (GetTickCount() - _afxTickCount > 60000)
  {
   CoFreeUnusedLibraries();
   _afxTickCount = ::GetTickCount();
  }
}

主要的释放还是调用了 AfxOleTerm，里面还是调用了

CoFreeUnusedLibraries();
::OleUninitialize();这两个函数。

在程序中用API编程可以借鉴MFC的内部函数~