控件的通知消息被送到哪里去了？

BOOL PASCAL CWnd::ReflectLastMsg(HWND hWndChild, LRESULT* pResult)

{

	// get the map, and if no map, then this message does not need reflection

	CHandleMap* pMap = afxMapHWND();

	if (pMap == NULL)

		return FALSE;



	// check if in permanent map, if it is reflect it (could be OLE control)

	CWnd* pWnd = (CWnd*)pMap->LookupPermanent(hWndChild);

	ASSERT(pWnd == NULL || pWnd->m_hWnd == hWndChild);

	if (pWnd == NULL)

	{

#ifndef _AFX_NO_OCC_SUPPORT

		// check if the window is an OLE control

		CWnd* pWndParent = (CWnd*)pMap->LookupPermanent(::GetParent(hWndChild));

		if (pWndParent != NULL && pWndParent->m_pCtrlCont != NULL)

		{

			// If a matching control site exists, it's an OLE control

			COleControlSite* pSite = (COleControlSite*)pWndParent->

				m_pCtrlCont->m_siteMap.GetValueAt(hWndChild);

			if (pSite != NULL)

			{

				CWnd wndTemp(hWndChild);

				wndTemp.m_pCtrlSite = pSite;

				LRESULT lResult = wndTemp.SendChildNotifyLastMsg(pResult);

				wndTemp.m_hWnd = NULL;

				return lResult;

			}

		}

#endif //!_AFX_NO_OCC_SUPPORT

		return FALSE;

	}



	// only OLE controls and permanent windows will get reflected msgs

	ASSERT(pWnd != NULL);

	return pWnd->SendChildNotifyLastMsg(pResult);

}

class CMyComboBox : public CComboBox

{

	DECLARE_DYNAMIC(CMyComboBox)

protected:

	DECLARE_MESSAGE_MAP()

	virtual BOOL OnCommand(WPARAM wParam, LPARAM lParam);

};

IMPLEMENT_DYNAMIC(CMyComboBox, CComboBox)



BEGIN_MESSAGE_MAP(CMyComboBox, CComboBox)

END_MESSAGE_MAP()



BOOL CMyComboBox::OnCommand(WPARAM wParam, LPARAM lParam)

{

	if (HIWORD(wParam) == EN_CHANGE)

		MessageBox(_T("OK"));

	return CComboBox::OnCommand(wParam, lParam);

}