改变打印机的打印端口

改变打印机的打印端口
uses Printers;
{$IFNDEF WIN32}
const MAX_PATH = 144;
{$ENDIF}
procedure TForm1.Button1Click(Sender: TObject);
var
pDevice : pChar;
pDriver : pChar;
pPort : pChar;
hDMode : THandle;
PDMode : PDEVMODE;
begin
if PrintDialog1.Execute then begin
GetMem(pDevice, cchDeviceName);
GetMem(pDriver, MAX_PATH);
GetMem(pPort, MAX_PATH);
Printer.GetPrinter(pDevice, pDriver, pPort, hDMode);
Printer.SetPrinter(pDevice, PDriver, 'FILE:', hDMode);
FreeMem(pDevice, cchDeviceName);
FreeMem(pDriver, MAX_PATH);
FreeMem(pPort, MAX_PATH);
Printer.BeginDoc;
Printer.Canvas.TextOut(100, 100, 'Delphi Is RAD!');
Printer.EndDoc;
end;
end;