在複寫的CWinApp::InitInstance()函式中新增下面程式碼

CMultiDocTemplate* pDocTemplate;
pDocTemplate = new CMultiDocTemplate(
	IDR_SMARTTTYPE,
	RUNTIME_CLASS(CCosiWorksDoc),
	RUNTIME_CLASS(CChildFrame), // custom MDI child frame
	RUNTIME_CLASS(CCosiWorksView));
AddDocTemplate(pDocTemplate);

然後呼叫AddDocTemplate，往CWinApp的成員m_pDocManager變數，文件管理器中新增模板

void CWinApp::AddDocTemplate(CDocTemplate* pTemplate)
{
	if (m_pDocManager == NULL)
		m_pDocManager = new CDocManager;
	m_pDocManager->AddDocTemplate(pTemplate);
}

CDocument* CWinApp::OpenDocumentFile(LPCTSTR lpszFileName)
{
	ENSURE_VALID(m_pDocManager);
	return m_pDocManager->OpenDocumentFile(lpszFileName);
}

CDocument* CDocManager::OpenDocumentFile(LPCTSTR lpszFileName)
{
	POSITION pos = m_templateList.GetHeadPosition();
	CDocTemplate* pBestTemplate = NULL;
	while (pos != NULL)
	{
		CDocTemplate* pTemplate = (CDocTemplate*)m_templateList.GetNext(pos);
		CDocTemplate::Confidence match;
		match = pTemplate->MatchDocType(szPath, pOpenDocument);
		if (match > bestMatch)
		{
			bestMatch = match;
			pBestTemplate = pTemplate;
		}
		if (match == CDocTemplate::yesAlreadyOpen)
			break;      // stop here
	}
	return pBestTemplate->OpenDocumentFile(szPath);

}

CDocument* CMultiDocTemplate::OpenDocumentFile(LPCTSTR lpszPathName,BOOL bMakeVisible)
{
	CDocument* pDocument = CreateNewDocument();
}

CDocument* CDocTemplate::CreateNewDocument()
{
	CDocument* pDocument = (CDocument*)m_pDocClass->CreateObject();
	return pDocument;
}

void CMultiDocTemplate::AddDocument(CDocument* pDoc)
{
	ASSERT_VALID(pDoc);

	CDocTemplate::AddDocument(pDoc);
	ASSERT(m_docList.Find(pDoc, NULL) == NULL); // must not be in list
	m_docList.AddTail(pDoc);
}

CDocument* CMultiDocTemplate::OpenDocumentFile(LPCTSTR lpszPathName,BOOL bMakeVisible)
{
	CDocument* pDocument = CreateNewDocument();
	CFrameWnd* pFrame = CreateNewFrame(pDocument, NULL);
}

CFrameWnd* CDocTemplate::CreateNewFrame(CDocument* pDoc, CFrameWnd* pOther)
{
	CFrameWnd* pFrame = (CFrameWnd*)m_pFrameClass->CreateObject();
}

CDocument* CMultiDocTemplate::OpenDocumentFile(LPCTSTR lpszPathName,BOOL bMakeVisible)
{
	CDocument* pDocument = CreateNewDocument();
	CFrameWnd* pFrame = CreateNewFrame(pDocument, NULL);
	pDocument->OnOpenDocument(lpszPathName);
}