HOWTO: How To Change the Work Offline Status of a Printer

MORE INFORMATION

While the Work Offline state is reflected by the condition of the PRINTER_STATUS_USER_INTERVENTION bit in a PRINTER_INFO structure's Status member, it is actually an attribute of the printer. As such, it is indicated and controlled by the PRINTER_ATTRIBUTE_WORK_OFFLINE bit of a PRINTER_INFO_2 structure's Attribute member. The Attribute member is a bitfield of Attribute bits for that printer. See the Win32 SDK online documents for a complete description of this structure member and its values.

Note that the Work Offline state of a printer in Windows is distinctly different from a printer being Off-line. The difference is that the PRINTER_ATTRIBUTE_WORK_OFFLINE attribute applies to a Window's Print Queue and effects how the queue behaves, while the Off-line status of a physical printer device is set on the device. The Off-line status of a physical printer can be determined from the Status members of either a PRINTER_INFO or JOB_INFO structure. See the Printer and Print Job status article in the REFERENCE section in this article for details.

Attribute information for a printer can be read and written by the GetPrinter and SetPrinter API functions. To determine if a printer is currently in the Work Offline state, perform a logical AND of the predefined constant PRINTER_ATTRIBUTE_WORK_OFFLINE and the Attribute member of a PRINTER_INFO_2 structure with the C language "&" operator. To change the Work Offline state of a printer, follow these steps:

1. Retrieve a PRINTER_INFO_2 structure for the printer by calling the GetPrinter function multiple times.
2. Change the PRINTER_ATTRIBUTE_WORK_OFFLINE bit of a PRINTER_INFO_2 structure's Attribute member. The following sample code illustrates how to clear or set a bit of this bitfield properly:

      if (pi2->Attributes & PRINTER_ATTRIBUTE_WORK_OFFLINE)
      {
          DWORD   dwStatusMask;
   
          /* set, so clear the bit */ 
          dwStatusMask = ~(DWORD)(PRINTER_ATTRIBUTE_WORK_OFFLINE);
          pi2->Attributes = pi2->Attributes & dwStatusMask;
      }
      else
      {
          /* not set, so set it */ 
          pi2->Attributes = pi2->Attributes |       PRINTER_ATTRIBUTE_WORK_OFFLINE;
      }
   						

3. Call the SetPrinter function to set the state of the printer by passing the modified structure.

Note that the PRINTER_ATTRIBUTE_WORK_OFFLINE attribute is not supported for printers in Windows NT.