Unicode C++ 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. Unicode C++

#include <CkJsonObjectW.h>
#include <CkFormatsW.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkJsonObjectW json;
    json.UpdateString(L"payload.text",L"https://www.chilkatsoft.com/order/12345");
    json.UpdateInt(L"render.moduleSize",6);

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

    json.UpdateString(L"output.path",L"qa_output/qr_caption.png");
    json.UpdateBool(L"output.overwrite",true);
    json.UpdateString(L"output.return",L"none");

    CkFormatsW fmt;
    CkJsonObjectW jsonOut;
    success = fmt.QrCode(L"generate",json,jsonOut);
    if (success == false) {
        wprintf(L"%s\n",fmt.lastErrorText());
        return;
    }

    wprintf(L"caption: %s\n",jsonOut.stringOf(L"measurements[0].text"));
    wprintf(L"caption scale: %d\n",jsonOut.IntOf(L"measurements[0].textScale"));
    wprintf(L"height added for the caption: %d pixels\n",jsonOut.IntOf(L"measurements[0].textBandPx"));
    wprintf(L"image: %d x %d pixels\n",jsonOut.IntOf(L"measurements[0].canvasWidth"),jsonOut.IntOf(L"measurements[0].canvasHeight"));

    //  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
    }