如何以编程方式打印到在 MFC 中的非默认打印机

#include <winspool.h>

// returns a DEVMODE and DEVNAMES for the printer name specified
BOOL GetPrinterDevice(LPTSTR pszPrinterName, HGLOBAL* phDevNames, HGLOBAL* phDevMode)
{
    // if NULL is passed, then assume we are setting app object‘s
    // devmode and devnames
    if (phDevMode == NULL || phDevNames == NULL)
        return FALSE;

    // Open printer
    HANDLE hPrinter;
    if (OpenPrinter(pszPrinterName, &hPrinter, NULL) == FALSE)
        return FALSE;

    // obtain PRINTER_INFO_2 structure and close printer
    DWORD dwBytesReturned, dwBytesNeeded;
    GetPrinter(hPrinter, 2, NULL, 0, &dwBytesNeeded);
    PRINTER_INFO_2* p2 = (PRINTER_INFO_2*)GlobalAlloc(GPTR,
        dwBytesNeeded);
    if (GetPrinter(hPrinter, 2, (LPBYTE)p2, dwBytesNeeded,
       &dwBytesReturned) == 0) {
       GlobalFree(p2);
       ClosePrinter(hPrinter);
       return FALSE;
    }
    ClosePrinter(hPrinter);

    // Allocate a global handle for DEVMODE
    HGLOBAL  hDevMode = GlobalAlloc(GHND, sizeof(*p2->pDevMode) +
       p2->pDevMode->dmDriverExtra);
    ASSERT(hDevMode);
    DEVMODE* pDevMode = (DEVMODE*)GlobalLock(hDevMode);
    ASSERT(pDevMode);

    // copy DEVMODE data from PRINTER_INFO_2::pDevMode
    memcpy(pDevMode, p2->pDevMode, sizeof(*p2->pDevMode) +
       p2->pDevMode->dmDriverExtra);
    GlobalUnlock(hDevMode);

    // Compute size of DEVNAMES structure from PRINTER_INFO_2‘s data
    DWORD drvNameLen = lstrlen(p2->pDriverName)+1;  // driver name
    DWORD ptrNameLen = lstrlen(p2->pPrinterName)+1; // printer name
    DWORD porNameLen = lstrlen(p2->pPortName)+1;    // port name

    // Allocate a global handle big enough to hold DEVNAMES.
    HGLOBAL hDevNames = GlobalAlloc(GHND,
        sizeof(DEVNAMES) +
        (drvNameLen + ptrNameLen + porNameLen)*sizeof(TCHAR));
    ASSERT(hDevNames);
    DEVNAMES* pDevNames = (DEVNAMES*)GlobalLock(hDevNames);
    ASSERT(pDevNames);

    // Copy the DEVNAMES information from PRINTER_INFO_2
    // tcOffset = TCHAR Offset into structure
    int tcOffset = sizeof(DEVNAMES)/sizeof(TCHAR);
    ASSERT(sizeof(DEVNAMES) == tcOffset*sizeof(TCHAR));

    pDevNames->wDriverOffset = tcOffset;
    memcpy((LPTSTR)pDevNames + tcOffset, p2->pDriverName,
        drvNameLen*sizeof(TCHAR));
    tcOffset += drvNameLen;

    pDevNames->wDeviceOffset = tcOffset;
    memcpy((LPTSTR)pDevNames + tcOffset, p2->pPrinterName,
        ptrNameLen*sizeof(TCHAR));
    tcOffset += ptrNameLen;

    pDevNames->wOutputOffset = tcOffset;
    memcpy((LPTSTR)pDevNames + tcOffset, p2->pPortName,
        porNameLen*sizeof(TCHAR));
    pDevNames->wDefault = 0;

    GlobalUnlock(hDevNames);
    GlobalFree(p2);   // free PRINTER_INFO_2

    // set the new hDevMode and hDevNames
    *phDevMode = hDevMode;
    *phDevNames = hDevNames;
    return TRUE;
}
				

// commdlg.h
// the first three members are character offsets from the beginning of the // structure pointing to the specific string
typedef struct tagDEVNAMES {
   WORD wDriverOffset;  // file name of driver (without extension)
   WORD wDeviceOffset;  // device name
   WORD wOutputOffset;  // device name of physical output medium
   WORD wDefault;       // DN_DEFAULTPRN if default printer chosen
} DEVNAMES;
				

void CMainFrame::OnActionSetnondefaultprinter() 
{
    HGLOBAL hDevMode = NULL;
    HGLOBAL hDevNames = NULL;
    if (GetPrinterDevice(_T("\\\\RED-PRN-25\\PRIV0006"), &hDevNames, &hDevMode))
        AfxGetApp()->SelectPrinter(hDevNames, hDevMode);
    else
        AfxMessageBox(_T("Failed to select custom printer"));
}
				

BOOL CNonDefPrinterView::OnPreparePrinting(CPrintInfo* pInfo)
{
    pInfo->m_bDirect = TRUE; // TRUE if bypassing Print Dialog
    return DoPreparePrinting(pInfo);
}
				

BOOL CNonDefPrinterView::OnPreparePrinting(CPrintInfo* pInfo)
{
    // set to non-default printer without changing default app printer
    HGLOBAL hDevMode;
    HGLOBAL hDevNames;

    if (!GetPrinterDevice(_T("\\\\RED-PRN-25\\PRIV0006"), &hDevNames, &hDevMode))
        AfxMessageBox(_T("GetPrinterDevice called failed\n"));

    pInfo->m_pPD->m_pd.hDevMode = hDevMode;
    pInfo->m_pPD->m_pd.hDevNames = hDevNames;
    pInfo->m_pPD->CreatePrinterDC();

    return TRUE;
}