Delphi ActiveX Requires Chilkat v11.7.0+

QR Code with a Text Caption

See more QR Code Examples

Demonstrates printing a line of text under a QR code, such as the order number or the address the code holds, so that a person can read it too. render.text turns the caption on and gives its value, which is printable ASCII and is drawn in a built-in font that needs no font files. The caption can go above or below the symbol, be aligned left, center or right, and be scaled. Delphi ActiveX

var
success: Integer;
json: TChilkatJsonObject;
fmt: TChilkatFormats;
jsonOut: TChilkatJsonObject;

begin
success := 0;

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

json := TChilkatJsonObject.Create(Self);
json.UpdateString('payload.text','https://www.chilkatsoft.com/order/12345');
json.UpdateInt('render.moduleSize',6);

//  The caption.  It need not be the same as the text in the QR code.
json.UpdateBool('render.text.enabled',1);
json.UpdateString('render.text.value','ORDER 12345');
//  position is "below" (the default) or "above".  alignment is "center" (the default), "left" or "right".
json.UpdateString('render.text.position','below');
//  Each dot of the caption's font is drawn this many pixels wide.
json.UpdateInt('render.text.scale',3);

json.UpdateString('output.path','qa_output/qr_caption.png');
json.UpdateBool('output.overwrite',1);
json.UpdateString('output.return','none');

fmt := TChilkatFormats.Create(Self);
jsonOut := TChilkatJsonObject.Create(Self);
success := fmt.QrCode('generate',json.ControlInterface,jsonOut.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(fmt.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('caption: ' + jsonOut.StringOf('measurements[0].text'));
Memo1.Lines.Add('caption scale: ' + IntToStr(jsonOut.IntOf('measurements[0].textScale')));
Memo1.Lines.Add('height added for the caption: ' + IntToStr(jsonOut.IntOf('measurements[0].textBandPx')) + ' pixels');
Memo1.Lines.Add('image: ' + IntToStr(jsonOut.IntOf('measurements[0].canvasWidth')) + ' x ' + IntToStr(jsonOut.IntOf('measurements[0].canvasHeight')) + ' pixels');

//  The image written to qa_output/qr_caption.png:

//  

//  Sample output:

//  caption: ORDER 12345
//  caption scale: 3
//  height added for the caption: 21 pixels
//  image: 222 x 243 pixels