Lazarus Pascal Requires Chilkat v11.7.0+

Choose the QR Code Version and Mask Pattern

See more QR Code Examples

Demonstrates fixing the QR version and the mask pattern. The version (1 to 40) is the size of the symbol: version 1 is 21 modules wide and each version adds 4. By default QrCode picks the smallest version that holds the data and the mask pattern that scores best under the QR standard. Fixing the version is useful when a series of codes must all be the same size, and minVersion and maxVersion bound the automatic choice instead. Lazarus Pascal

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Formats,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  fmt: TFormats;
  json: TJsonObject;
  jsonOut: TJsonObject;
  json2: TJsonObject;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  fmt := TFormats.Create;
  json := TJsonObject.Create;
  jsonOut := TJsonObject.Create;
  json.UpdateString('payload.text','https://www.chilkatsoft.com/');

  //  Automatic: the smallest version that holds the text, and the best-scoring mask.
  success := fmt.QrCode('generate',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(fmt.LastErrorText);
      Exit;
    end;
  WriteLn('automatic: version ' + jsonOut.IntOf('symbols[0].selectedEncoding.version') + ', ' + jsonOut.IntOf('symbols[0].dimensions.modulesWide') + ' modules wide, mask '
       + jsonOut.IntOf('symbols[0].selectedEncoding.mask'));

  //  A fixed version.  The call fails with capacityExceeded if the text does not fit it.
  json.UpdateInt('encoding.qr.version',8);
  success := fmt.QrCode('generate',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(fmt.LastErrorText);
      Exit;
    end;
  WriteLn('version 8: version ' + jsonOut.IntOf('symbols[0].selectedEncoding.version') + ', ' + jsonOut.IntOf('symbols[0].dimensions.modulesWide') + ' modules wide, mask '
       + jsonOut.IntOf('symbols[0].selectedEncoding.mask'));

  //  A fixed mask pattern, 0 to 7.  Every mask gives a valid symbol holding the same data.
  json.UpdateInt('encoding.qr.mask',5);
  success := fmt.QrCode('generate',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(fmt.LastErrorText);
      Exit;
    end;
  WriteLn('version 8, mask 5: version ' + jsonOut.IntOf('symbols[0].selectedEncoding.version') + ', mask ' + jsonOut.IntOf('symbols[0].selectedEncoding.mask'));

  //  Bounds for the automatic choice: no smaller than version 4, no larger than version 10.
  json2 := TJsonObject.Create;
  json2.UpdateString('payload.text','https://www.chilkatsoft.com/');
  json2.UpdateInt('encoding.qr.minVersion',4);
  json2.UpdateInt('encoding.qr.maxVersion',10);
  success := fmt.QrCode('generate',json2,jsonOut);
  if (success = False) then
    begin
      WriteLn(fmt.LastErrorText);
      Exit;
    end;
  WriteLn('minVersion 4: version ' + jsonOut.IntOf('symbols[0].selectedEncoding.version'));

  //  The four symbols, in the order they were made.  The second and the third hold the same data
  //  in the same version and differ only in the mask:

  //  

  //  Sample output:

  //  automatic: version 3, 29 modules wide, mask 2
  //  version 8: version 8, 49 modules wide, mask 2
  //  version 8, mask 5: version 8, mask 5
  //  minVersion 4: version 4


  fmt.Free;
  json.Free;
  jsonOut.Free;
  json2.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.