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Changing the port of a printer

Question:

How can I change the port a given printer will use in code?

Answer:

You can use the SetPrinter method of TPrinter to change the port. The following example demonstrates changing the port to print to a file.

Example:

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;