How To Change the Default Source of Printer Programmatically

MORE INFORMATION

   SetPrinter(HANDLE hPrinter, DWORD dwLevel, LPBYTE lpbPrinter, DWORD
dwCommand)
						

Sample Program (DLL to Change the Default Source of Printer)

   #include "stdio.h"
   #include <windows.h>

   BOOL APIENTRY DllMain(HANDLE hInst, DWORD ul_reason_being_called, LPVOID
   lpReserved)
   {
        return 1;
        UNREFERENCED_PARAMETER(hInst);
        UNREFERENCED_PARAMETER(ul_reason_being_called);
        UNREFERENCED_PARAMETER(lpReserved);
   }


   #define ErrReturn   if (GetLastError()) {ClosePrinter(hPrinter);
   printf("error"); return -1;}

   short FindID(LPPRINTER_INFO_2 pPrinter, int flg);

   BOOL MyFreeMem(LPVOID pMem)
   {
      return VirtualFree(pMem, 0, MEM_RELEASE);
   }

   #define UPPER_BIN 1
   #define LOWER_BIN 2


   int APIENTRY chgbin(char *ptrname, int flg)
   {
      HANDLE   hPrinter = NULL;
      DWORD    cbBuf;
      DWORD    pcbNeeded = 0;
      LPTSTR   pPrintername;
      short    nSource;

      pPrintername = ptrname;

      PRINTER_DEFAULTS pd;
      ZeroMemory(&pd, sizeof(pd));
      pd.DesiredAccess = PRINTER_ALL_ACCESS;

      int result1 = OpenPrinter(pPrintername,&hPrinter, &pd);
      ErrReturn;
      int result = GetPrinter(hPrinter, 2, NULL, 0, &pcbNeeded);
      DWORD Error = GetLastError( );

       if( Error == ERROR_INSUFFICIENT_BUFFER )
       {
      BOOL  bRet = FALSE;
                   HANDLE  hMem = NULL;
      LPPRINTER_INFO_2  pPrinter;

           hMem = GlobalAlloc(GHND, pcbNeeded);
           if (hMem) pPrinter = (LPPRINTER_INFO_2)GlobalLock(hMem);
           cbBuf = pcbNeeded;
      DWORD cbNeeded;
      if (GetPrinter(hPrinter, 2, (LPBYTE)pPrinter, pcbNeeded, &cbNeeded))
      {
         if ((nSource = FindID(pPrinter,flg)) < 0) return -1;

         pPrinter->pDevMode->dmDefaultSource = nSource;
         pPrinter->pDevMode->dmFields = DM_DEFAULTSOURCE;

         DocumentProperties(NULL,hPrinter,pPrintername,pPrinter-
   >pDevMode,pPrinter->pDevMode,
               DM_IN_BUFFER|DM_OUT_BUFFER);
         SetPrinter(hPrinter,2,(unsigned char *)pPrinter,0);

         MyFreeMem(pPrinter);
         ClosePrinter(hPrinter);
      }
       }

       Error = GetLastError( );
       return 0;
   }


   typedef struct _tagDevCaps
   {
      TCHAR    pPrinterName[80];
      TCHAR    pPort[80];
      WORD  wCurCap;
      WORD    wCurPlatForm;
      HINSTANCE hDriver;   //only used if on Win32s;
      DWORD  (CALLBACK* pfnDevCaps) (
         LPTSTR    pDevice,   // address of device-name string
         LPTSTR    pPort,  // address of port-name string
         UINT      fwCapability, // device capability to query
         LPTSTR    pOutput,   // address of the output
         LPDEVMODE pDevMode   // address of structure with device data
      );
   } DEVCAPS;

   LPVOID MyAllocMem(DWORD cb)
   {
      return VirtualAlloc(NULL, cb, MEM_RESERVE|MEM_COMMIT,
                          PAGE_READWRITE);
   }

   #define MAX_AMOUNT      256
   #define MAX_BINS   16

   short FindID(LPPRINTER_INFO_2 pPrinter, int flg)
   {
      DEVCAPS MyDevCaps;
      MyDevCaps.hDriver = NULL;
      MyDevCaps.pfnDevCaps = NULL;
      BOOL bRet = FALSE;

      lstrcpy(MyDevCaps.pPrinterName,  pPrinter->pPrinterName);
      lstrcpy(MyDevCaps.pPort,  pPrinter->pPortName);
      MyDevCaps.pfnDevCaps = (LPFNDEVCAPS)&DeviceCapabilities;

      DWORD       dwBufSize = 0;
      BOOL        bResult = 1;
      WORD FAR    *pawBinList;

      if (MyDevCaps.pfnDevCaps)
      {
          // get number of bins
          dwBufSize = MyDevCaps.pfnDevCaps ((LPTSTR
   )MyDevCaps.pPrinterName,
   (LPTSTR )MyDevCaps.pPort, (WORD)DC_BINS,
                                      (LPTSTR )NULL, (LPDEVMODE)NULL);

          pawBinList = (WORD FAR *)MyAllocMem(dwBufSize* (sizeof(WORD)));

          // fill buffer with bin list
          MyDevCaps.pfnDevCaps ((LPTSTR )MyDevCaps.pPrinterName, (LPTSTR
   )MyDevCaps.pPort, (WORD)DC_BINS,
                          (LPTSTR )pawBinList, (LPDEVMODE)NULL);

          // display bin info
          // protects from bad drivers

           if ((dwBufSize > 0) && (dwBufSize < MAX_AMOUNT))
           {
         for (int i=0; i< (int)dwBufSize;i++)
         {
              if (pawBinList[i] < MAX_AMOUNT)
              {
                       if (pawBinList[i] < MAX_BINS)
             {
                    if (flg == UPPER_BIN && pawBinList[i] == UPPER_BIN)
               return (pawBinList[i]);
                 else if (flg == LOWER_BIN && pawBinList[i] == LOWER_BIN)
               return (pawBinList[i]);
             }
              }
         }
           }
          // clean up
          MyFreeMem(pawBinList);

          return (-1);
      }
      return (-1);
   }
				

In the FoxPro Application

   DECLARE integer chgbin IN c:\bin.DLL STRING, INTEGER

   ** 1 = Upper   2 = Lower
   retval = chgbin("HP LaserJet 4Si MX",2)

   USE CUSTOMER
   LIST TO PRINT
				

Sample Program (Notes)

• To create a .dll file in Visual C++, please refer to Help in Microsoft Visual C++ 4.0.
• The Chgbin.dll should be in the same directory as your project, or should be in the path of the Windows Win32 directory.