Merlin's Delphi Forge

You shouldn’t have too much problem opening a Delphi 4 form in Delphi 2 but you won’t have luck opening a 32 bit or C++ Builder form in Delphi 1. The only way is to save the file in text form. Delphi 5 can do this automatically but in all the previous versions you have to do this all by yourself, form by form.
This is a full featured program that will do all the work for you. The source is dumped into Public Domain.

(* DfmToTxt 1.0
**
** Author: Jacob Dybala (m3Rlin). Public Domain
**   <m3rlin@programmer.net>
**
** Created : January 2 2000
** Modified: April 12 2000
*)
program DfmToTxt; 

{$apptype console} { Generate console application }
{$debuginfo off}
{$localsymbols off}
{$optimizations on}
{$rangechecks off} 

uses
  Classes, SysUtils; 

var
  sNewFileName: string;
  strInput, strOutput: TStream;
begin
  { Initialize streams }
  strInput := nil;
  strOutput := nil; 

  { Get commandline parameters }
  if (ParamCount > 2) or (ParamCount = 0) then begin
    WriteLn('DfmToTxt 1.0');
    WriteLn('By Jacob Dybala (m3Rlin). Public Domain.');
    WriteLn;
    WriteLn('Usage: DfmToTxt <input /> <output></output>');
    Exit;
  end else if not FileExists(ParamStr(1)) then begin
    WriteLn(Format('Error: %s can not be found.', [sNewFileName]));
    Exit;
  end if ExtractFileExt(ParamStr(1) <> '.dfm') then begin
    WriteLn('Error: Input file must be a .dfm (Delphi Form) file');
    Exit;
end; 

if ParamCount = 1 then begin
  sNewFileName := ParamStr(1);
  sNewFileName := ChangeFileExt(sNewFileName, '.txt');
end else begin
  sNewFileName := ParamStr(2);
  if FileExists(sNewFileName) then begin
    WriteLn(Format('Error: A file named %s already exists.', [sNewFileName]));
    Exit;
  end;
end; 

{ Main code }
try
  try
    strInput := TFileStream.Create(ParamStr(1), fmOpenRead);
    strOutput := TFileStream.Create(sNewFileName, fmCreate);
  expect
    Write('Error: Failed creating ');
    WriteLn(sNewFileName);
    Exit;
  end;
  ObjectResourceToText(strInput, strOutput);
  finally
    strInput.Free;
    strOutput.Free;
  end;
end;

This is the harder way to print text in Delphi If you want to do it the easier way check out tip 4.1. Well, if for some reasons you may want to print using the Windows API here’s the code:

Code 1:

uses
  Printers, WinSpool;
...
var
  aDriver, aPort, aPrinterName: array[0..255] of Char; { aDriver and aPort won't be used }
  iSize, iN: Integer;
  Info: PAddJobInfo1;
  fPrinter: TextFile;
  hPrinter: THandle;
begin
  Printer.GetPrinter(aPrinterName, aDriver, aPort, hPrinter);
  OpenPrinter(aPrinterName, hPrinter, nil);
  try
    AddJob(hPrinter, 1, nil, 0, iSize); { Get buffer size }
    GetMem(Info, iSize);
    try
      { This function will return the name of the file we can write to }
      AddJob(hPrinter, 1, Info, iSize, iN);
      { Now write to the file }
      AssignFile(fPrinter, Info^.Path);
      Rewrite(fPrinter);
      try
        WriteLn(fPrinter, 'Hello world!');
        WriteLn(fPrinter, 'This is text will be printed...');
      finally
        CloseFile(fPrinter);
      end;
      { Put the file into the printing line, after that Windows will delete it }
      ScheduleJob(hPrinter, Info^.JobId);
    finally
      FreeMem(Info);
    end;
  finally
    ClosePrinter(hPrinter);
  end;
end;

Code 2:

{ Will work only if the printer is on LPT1 (almost always:-) }
...
LPTHandle := CreateFile('LPT1', GENERIC_WRITE, 0, PSecurityAttributes(nil),
OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
...

Then use WriteFile() to send text or:

...
while not TransmitCommChar(LPTHandle, CharToSend) do
  Application.ProcessMessages;

(* This code will send characters to the printer waiting for each one of them
** to be taken care of.
*)