获取打印机的打印任务列表

如何在程序里判断一个打印作业已经进入打印队列（也就是可以在打印管理程序里看到该作业的信息），或者说如何察看打印队列里已有的作业信息？
看下面的这个例程。还有测试代码。
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;
for i:=0 to pcReturned-1 do begin
if aJobs.pDocument <> Nil then begin
SetLength(Result, Length(Result)+1);
Result[Length(Result)-1] := aJobs;
end;
end;
end;
测试例子：
1- 创建工程有 StringGrid 和一个 Timer.
2- StringGrid 'ColCount' and “RowCount” 值为 20
3- Timer的 “Interval” 属性值 500.
4- “OnTime” 实践中写这个代码
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('/ibmserverLaserJet 1100');//正在打印的打印机名字，这里我的打印机时网打。这里你要自己改
for i:=0 to Length(aJobs)-1 do begin
StringGrid1.Cells[i,0] := aJobs.pPrinterName;
StringGrid1.Cells[i,1] := aJobs.pMachineName;
StringGrid1.Cells[i,2] := aJobs.pUserName;
StringGrid1.Cells[i,3] := aJobs.pDocument;
StringGrid1.Cells[i,4] := aJobs.pDatatype;
StringGrid1.Cells[i,5] := aJobs.pStatus;
StringGrid1.Cells[i,6] := IntToStr(aJobs.Status);
case aJobs.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- 运行程序，打印程序测之
　
OK
⌒_⌒