HOWTO: Determine the Type of Handle Retrieved from OpenPrinter

• Microsoft Win32 Application Programming Interface (API), used with:
  • Microsoft Windows NT, versions 3.5, 3.51, 4.0
  • Microsoft Windows 95

SUMMARY

OpenPrinter returns a valid handle when a printer name or a server name is passed to it. Sometimes you might need to determine if the returned handle is a handle to a printer, because some Win32 spooler functions only accept printer handles and will fail on server handles. The following code determines if a handle is a printer handle:

   BOOL IsPrinterHandle( HANDLE hPrinter)
   {

       DWORD       cbNeeded;
       DWORD       Error;
       BOOL        bRet = TRUE;

       if( !GetPrinter(hPrinter, 2, (LPBYTE)NULL, 0, &cbNeeded ))
       {
           Error = GetLastError( );
        bRet = FALSE;

           if( Error == ERROR_INSUFFICIENT_BUFFER )
           {

             // Expect this for a valid printer handle.
                   bRet = TRUE;

           }

       }
       return bRet;

   } 

Additional query words: kbDSupport kbdss kbGDI kbPrinting

Keywords : kbNTOS350 kbNTOS351 kbNTOS400 kbSDKWin32 kbWinOS95 kbDSupport
Version : winnt:3.5,3.51,4.0
Platform : winnt
Issue type : kbhowto