继承类自定义函数以修改打印方向debug出错release正常

原类中的函数是这样的：

void CBCGPGridCtrl::Print ()

{

	// Printing without the Document/View framework

	ASSERT_VALID(this);



	CDC dc;

	CPrintDialog printDlg(FALSE);

	 

	if (printDlg.DoModal() == IDCANCEL)

		return;

	

	dc.Attach(printDlg.GetPrinterDC());

	dc.m_bPrinting = TRUE;



	CString strTitle;

	strTitle.LoadString(AFX_IDS_APP_TITLE);



	DOCINFO di;

	::ZeroMemory (&di, sizeof (DOCINFO));

	di.cbSize = sizeof (DOCINFO);

	di.lpszDocName = strTitle;



	BOOL bPrintingOK = dc.StartDoc(&di);



	m_bIsPrinting = TRUE;

	m_pPrintDC = &dc;



	CPrintInfo printInfo;

	printInfo.m_rectDraw.SetRect(0,0,

		dc.GetDeviceCaps(HORZRES),

		dc.GetDeviceCaps(VERTRES));



	// -----------------------------------------

	// Prepare page for printing, calc page size

	// -----------------------------------------

	int nFirstItem = 0;// By default print all grid items

	int nLastItem = GetTotalItems () - 1;// from first row to the last

	OnPreparePrintPages (&printInfo, nFirstItem, nLastItem);



	OnBeginPrinting(&dc, &printInfo);



	// ---------------

	// Set up margins:

	// ---------------

	CRect rectMargins = OnGetPageMargins (&dc, &printInfo);

	printInfo.m_rectDraw.DeflateRect (&rectMargins);



	int nPagesCount = OnCalcPrintPages (&dc, &printInfo);

	printInfo.SetMaxPage (nPagesCount);



	CRect rectDraw = printInfo.m_rectDraw;



	for (printInfo.m_nCurPage = printInfo.GetMinPage(); printInfo.m_nCurPage <= printInfo.GetMaxPage() && bPrintingOK; printInfo.m_nCurPage++)

	{

		printInfo.m_rectDraw = rectDraw;



		dc.StartPage();



		OnPrint(&dc, &printInfo);

		bPrintingOK = (dc.EndPage() > 0);

	}

	OnEndPrinting(&dc, &printInfo);



	if (bPrintingOK)

		dc.EndDoc();

	else

		dc.AbortDoc();



	m_bIsPrinting = FALSE;

	m_pPrintDC = NULL;



	dc.DeleteDC();



	AdjustLayout ();

}

继承原类的新函数是这样的：

class CBCGPGridCtrlEx : public CBCGPGridCtrl

{

public:

	void CBCGPGridCtrl::Print ()

	{

		// Printing without the Document/View framework

		ASSERT_VALID(this);



		PRINTDLG pd;

		LPDEVMODE lpDevMode;



		CDC dc;

		CPrintDialog printDlg(FALSE);

	 

		pd.lStructSize = (DWORD)sizeof(PRINTDLG);

		if(AfxGetApp()->GetPrinterDeviceDefaults(&pd))

		{

			lpDevMode = (LPDEVMODE)GlobalLock(pd.hDevMode);

			if(lpDevMode)

			{

				lpDevMode->dmPaperSize = DMPAPER_A4;

				lpDevMode->dmOrientation = dmOrientation;

			}

			GlobalUnlock(pd.hDevMode);

		}

		printDlg.m_pd.hDevMode = pd.hDevMode;



		if (printDlg.DoModal() == IDCANCEL)

			return;

	

		dc.Attach(printDlg.GetPrinterDC());

		dc.m_bPrinting = TRUE;



		CString strTitle;

		strTitle.LoadString(AFX_IDS_APP_TITLE);



		DOCINFO di;

		::ZeroMemory (&di, sizeof (DOCINFO));

		di.cbSize = sizeof (DOCINFO);

		di.lpszDocName = strTitle;



		BOOL bPrintingOK = dc.StartDoc(&di);



		m_bIsPrinting = TRUE;

		m_pPrintDC = &dc;



		CPrintInfo printInfo;

		printInfo.m_rectDraw.SetRect(0,0,

			dc.GetDeviceCaps(HORZRES),

			dc.GetDeviceCaps(VERTRES));



		// -----------------------------------------

		// Prepare page for printing, calc page size

		// -----------------------------------------

		int nFirstItem = 0;// By default print all grid items

		int nLastItem = GetTotalItems () - 1;// from first row to the last

		OnPreparePrintPages (&printInfo, nFirstItem, nLastItem);



		OnBeginPrinting(&dc, &printInfo);



		// ---------------

		// Set up margins:

		// ---------------

		CRect rectMargins = OnGetPageMargins (&dc, &printInfo);

		printInfo.m_rectDraw.DeflateRect (&rectMargins);



		int nPagesCount = OnCalcPrintPages (&dc, &printInfo);

		printInfo.SetMaxPage (nPagesCount);



		CRect rectDraw = printInfo.m_rectDraw;



		for (printInfo.m_nCurPage = printInfo.GetMinPage(); printInfo.m_nCurPage <= printInfo.GetMaxPage() && bPrintingOK; printInfo.m_nCurPage++)

		{

			printInfo.m_rectDraw = rectDraw;



			dc.StartPage();



			OnPrint(&dc, &printInfo);

			bPrintingOK = (dc.EndPage() > 0);

		}

		OnEndPrinting(&dc, &printInfo);



		if (bPrintingOK)

			dc.EndDoc();

		else

			dc.AbortDoc();



		m_bIsPrinting = FALSE;

		m_pPrintDC = NULL;



		dc.DeleteDC();



		AdjustLayout ();

	}

}

因为原来的类CBCGPGridCtrl::Print()函数不支持打印方向控制，所以自己继承这个类然后重写打印函数，可通过传入参数以实现打印方向控制，现在问题是调用时都没有问题，但是在DEBUG模式退出程序后，会出现调试错误，
函数：void AFXAPI AfxGlobalFree(HGLOBAL hGlobal)，中断的行是ASSERT(GlobalFlags(hGlobal) != GMEM_INVALID_HANDLE);
如果我不添加修改打印方向的那段代码，都没有任何问题，估计是修改打印方向后，有内存没有正确释放，请各位高手帮忙看看该怎么改这段代码，谢谢！