I need to implement duplex printing on a printer. I set the DEVMODE structure in the printer driver with the dmDuplex parameter

int dvmSize=DocumentProperties(GetForegroundWindow(),hPrinter,(LPWSTR)(printerName.c_str()),NULL,NULL,0);
DEVMODE *dvmSettings = (DEVMODE*) GlobalAlloc(GPTR,dvmSize);
DEVMODE *dvMode = (DEVMODE*) GlobalAlloc(GPTR,dvmSize);
DocumentProperties(GetForegroundWindow(),hPrinter,(LPWSTR)(printerName.c_str()),dvmSettings,NULL,DM_OUT_BUFFER);
dvmSettings->dmDuplex=DMDUP_HORIZONTAL;
dvmSettings->dmFields=DM_DUPLEX;
DocumentProperties(GetForegroundWindow(),hPrinter,(LPWSTR)(printerName.c_str()),dvMode,dvmSettings,DM_IN_BUFFER|DM_OUT_BUFFER);

As far as I understand, there are 2 ways of implementation. Via WritePrinter or create a HDC using CreateDC passing dvMode and draw directly to the context. The second way is more convenient for me, but will it work? I'm asking because I can't test it right now and I need to know if it will work.

CodePudding user response：

As far as I'm concerned, it will work.

You could call the CreateDC or PrintDlgEx function to get the printer DC.

If your application calls the CreateDC function, it must supply a driver and port name. To retrieve these names, call the GetPrinter or EnumPrinters function.

If your application calls the PrintDlgEx function and specifies the PD_RETURNDC value in the Flags member of the PRINTDLGEX structure, the system returns a handle to a device context for the printer selected by the user.

For more details I suggest you could refer to the Docs:

1. https://docs.microsoft.com/en-us/windows/win32/printdocs/sending-data-directly-to-a-printer

2. https://docs.microsoft.com/zh-cn/windows/win32/printdocs/gdi-printing

3. https://docs.microsoft.com/en-us/windows/win32/printdocs/printer-output

4. https://docs.microsoft.com/zh-cn/windows/win32/dlgbox/using-common-dialog-boxes