C++ Requires Chilkat v11.7.0+

QR Code with Non-English Text (UTF-8 and ECI)

See more QR Code Examples

Demonstrates text outside ASCII. QrCode always stores text as UTF-8 bytes, which is what phones expect. A QR code can also say so explicitly with an ECI header: setting encoding.eci to 26 declares the bytes to be UTF-8, for readers that would otherwise assume another character set. The header costs a little space, and a few older readers do not understand it, so it is off by default. C++

#include <CkStringBuilder.h>
#include <CkJsonObject.h>
#include <CkFormats.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.

    //  The text is "Gruesse aus Muenchen" written with u-umlaut and sharp s.  It is given here with
    //  JSON escapes only so that this source is plain ASCII.  Decode turns the escapes into characters.
    CkStringBuilder sbText;
    sbText.Append("Gr\u00fc\u00dfe aus M\u00fcnchen");
    sbText.Decode("json","utf-8");

    CkJsonObject json;
    json.UpdateSb("payload.text",sbText);
    json.UpdateString("output.path","qa_output/qr_utf8.png");
    json.UpdateBool("output.overwrite",true);
    json.UpdateString("output.return","none");

    CkFormats fmt;
    CkJsonObject jsonOut;
    success = fmt.QrCode("generate",json,jsonOut);
    if (success == false) {
        std::cout << fmt.lastErrorText() << "\r\n";
        return;
    }

    //  17 characters, three of which take two bytes in UTF-8.
    std::cout << "characters: " << sbText.get_Length() << "\r\n";
    std::cout << "bytes encoded: " << jsonOut.IntOf("symbols[0].payloadBytes") << "\r\n";
    std::cout << "ECI header: " << jsonOut.HasMember("symbols[0].selectedEncoding.eci") << "\r\n";

    //  Without an ECI header (qa_output/qr_utf8.png):

    //  

    //  The same text with an ECI header declaring UTF-8.
    json.UpdateInt("encoding.eci",26);
    json.UpdateString("output.path","qa_output/qr_utf8_eci.png");
    success = fmt.QrCode("generate",json,jsonOut);
    if (success == false) {
        std::cout << fmt.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "with encoding.eci = 26, ECI header: " << jsonOut.HasMember("symbols[0].selectedEncoding.eci") << ", value " << jsonOut.IntOf("symbols[0].selectedEncoding.eci") << "\r\n";

    //  With the ECI header (qa_output/qr_utf8_eci.png).  Both scan as the same text:

    //  

    //  Sample output:

    //  characters: 17
    //  bytes encoded: 20
    //  ECI header: False
    //  with encoding.eci = 26, ECI header: True, value 26
    }