List Print Jobs in a Printer Queue

uses

  Winspool, Printers;

function GetCurrentPrinterHandle: THandle;

var

  Device, Driver, Port: array[0..255] of Char;

  hDeviceMode: THandle;

begin

  Printer.GetPrinter(Device, Driver, Port, hDeviceMode);

  if not OpenPrinter(@Device, Result, nil) then

   RaiseLastWin32Error;

end;

function SavePChar(p: PChar): PChar;

const

  error: PChar = 'Nil';

begin

  if not Assigned(p) then

   Result := error

  else

   Result := p;

end;

procedure TForm1.Button1Click(Sender: TObject);

type

  TJobs = array [0..1000] of JOB_INFO_1;

  PJobs = ^TJobs;

var

  hPrinter: THandle;

  bytesNeeded, numJobs, i: Cardinal;

  pJ: PJobs;

begin

  hPrinter := GetCurrentPrinterHandle;

  try

   EnumJobs(hPrinter, 0, 1000, 1, nil, 0, bytesNeeded, numJobs);

   pJ := AllocMem(bytesNeeded);

   if not EnumJobs(hPrinter, 0, 1000, 1, pJ, bytesNeeded, bytesNeeded, numJobs) then

    RaiseLastWin32Error;

   memo1.Clear;

   if numJobs = 0 then

    memo1.Lines.Add('No jobs in queue')

   else

    for i := 0 to Pred(numJobs) do

     memo1.Lines.Add(Format('Printer %s, Job %s, Status (%d): %s',

    [SavePChar(pJ^[i].pPrinterName), SavePChar(pJ^[i].pDocument), pJ^[i].Status, SavePChar(pJ^[i].pStatus)]));

  finally

   ClosePrinter(hPrinter);

  end;

end;