Title: Jobs information (an easy way)?
Question: How to retrieve jobs information that is in the printer spooler?
Answer:
With Windows it is very easy to monitor the printed jobs. But sometimes and for a good reason the user need to monitor those jobs from inside the application. How? The answer is using the "EnumJobs" Windows API to retrieve the information (Job Name-Status-date-time...etc). To simplify the use of this Windows API I developed an easy function that receive the printer name and return an array of a structure, which represent the information needed. Here is the code for this function:
uses WinSpool;
..
type JOB_INFO_1_ARRAY = Array of JOB_INFO_1;
..
Function GetSpoolerJobs(sPrinterName : String) : JOB_INFO_1_ARRAY;
var
i : Integer;
hPrinter : THandle;
bResult : Boolean;
cbBuf : DWORD;
pcbNeeded : DWORD;
pcReturned : DWORD;
aJobs : Array[0..99] of JOB_INFO_1;
begin
cbBuf := 1000;
bResult := OpenPrinter(PChar(sPrinterName), hPrinter, Nil);
if NOT bResult then begin
ShowMessage('Error opening the printer');
exit;
end;
bResult := EnumJobs(hPrinter,0,Length(aJobs),1,@aJobs,cbBuf,pcbNeeded,pcReturned);
if NOT bResult then begin
ShowMessage('Error Getting Jobs information');
exit;
end;
ClosePrinter(hPrinter);
for i:=0 to pcReturned-1 do begin
if aJobs[i].pDocument Nil then begin
SetLength(Result, Length(Result)+1);
Result[Length(Result)-1] := aJobs[i];
end;
end;
end;
An example of use:
1- Create a new project with a StringGrid and a Timer.
2- Set ColCount and RowCount properties of the string grid to 20.
3- Set the Interval property of the Timer to 500.
4- On the OnTime event of the timer write the following code :
procedure TForm1.Timer1Timer(Sender: TObject);
var
i, ii : Integer;
aJobs : JOB_INFO_1_ARRAY;
begin
for i:=0 to StringGrid1.ColCount-1 do
for ii:=0 to StringGrid1.RowCount-1 do StringGrid1.Cells[i,ii] := '';
aJobs := GetSpoolerJobs('HP LaserJet 6L PCL');
for i:=0 to Length(aJobs)-1 do begin
StringGrid1.Cells[i,0] := aJobs[i].pPrinterName;
StringGrid1.Cells[i,1] := aJobs[i].pMachineName;
StringGrid1.Cells[i,2] := aJobs[i].pUserName;
StringGrid1.Cells[i,3] := aJobs[i].pDocument;
StringGrid1.Cells[i,4] := aJobs[i].pDatatype;
StringGrid1.Cells[i,5] := aJobs[i].pStatus;
StringGrid1.Cells[i,6] := IntToStr(aJobs[i].Status);
case aJobs[i].Status of
JOB_STATUS_PAUSED: StringGrid1.Cells[i,6] := 'JOB_STATUS_PAUSED';
JOB_STATUS_ERROR: StringGrid1.Cells[i,6] := 'JOB_STATUS_ERROR';
JOB_STATUS_DELETING: StringGrid1.Cells[i,6] := 'JOB_STATUS_DELETING';
JOB_STATUS_SPOOLING: StringGrid1.Cells[i,6] := 'JOB_STATUS_SPOOLING';
JOB_STATUS_PRINTING: StringGrid1.Cells[i,6] := 'JOB_STATUS_PRINTING';
JOB_STATUS_OFFLINE: StringGrid1.Cells[i,6] := 'JOB_STATUS_OFFLINE';
JOB_STATUS_PAPEROUT: StringGrid1.Cells[i,6] := 'JOB_STATUS_PAPEROUT';
JOB_STATUS_PRINTED: StringGrid1.Cells[i,6] := 'JOB_STATUS_PRINTED';
JOB_STATUS_DELETED: StringGrid1.Cells[i,6] := 'JOB_STATUS_DELETED';
JOB_STATUS_BLOCKED_DEVQ: StringGrid1.Cells[i,6] := 'JOB_STATUS_BLOCKED_DEVQ';
JOB_STATUS_USER_INTERVENTION: StringGrid1.Cells[i,6] := 'JOB_STATUS_USER_INTERVENTION';
JOB_STATUS_RESTART: StringGrid1.Cells[i,6] := 'JOB_STATUS_RESTART';
JOB_POSITION_UNSPECIFIED: StringGrid1.Cells[i,6] := 'JOB_POSITION_UNSPECIFIED';
else StringGrid1.Cells[i,6] := 'Unknown status...';
end;
end;
StringGrid1.Refresh;
end;
5- Run this project and try to print any documents using MSWord or any Windows Aplication and WATCH the stringgrid.
Thats all. Any comments are welcome.