Delphi DLL 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 DLL

var
success: Boolean;
json: HCkJsonObject;
fmt: HCkFormats;
jsonOut: HCkJsonObject;

begin
success := False;

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

json := CkJsonObject_Create();
CkJsonObject_UpdateString(json,'payload.text','https://www.chilkatsoft.com/order/12345');
CkJsonObject_UpdateInt(json,'render.moduleSize',6);

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

CkJsonObject_UpdateString(json,'output.path','qa_output/qr_caption.png');
CkJsonObject_UpdateBool(json,'output.overwrite',True);
CkJsonObject_UpdateString(json,'output.return','none');

fmt := CkFormats_Create();
jsonOut := CkJsonObject_Create();
success := CkFormats_QrCode(fmt,'generate',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkFormats__lastErrorText(fmt));
    Exit;
  end;

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

CkJsonObject_Dispose(json);
CkFormats_Dispose(fmt);
CkJsonObject_Dispose(jsonOut);