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 <C_CkStringBuilder.h>
#include <C_CkJsonObject.h>
#include <C_CkFormats.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkStringBuilder sbText;
    HCkJsonObject json;
    HCkFormats fmt;
    HCkJsonObject jsonOut;

    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.
    sbText = CkStringBuilder_Create();
    CkStringBuilder_Append(sbText,"Gr\u00fc\u00dfe aus M\u00fcnchen");
    CkStringBuilder_Decode(sbText,"json","utf-8");

    json = CkJsonObject_Create();
    CkJsonObject_UpdateSb(json,"payload.text",sbText);
    CkJsonObject_UpdateString(json,"output.path","qa_output/qr_utf8.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) {
        printf("%s\n",CkFormats_lastErrorText(fmt));
        CkStringBuilder_Dispose(sbText);
        CkJsonObject_Dispose(json);
        CkFormats_Dispose(fmt);
        CkJsonObject_Dispose(jsonOut);
        return;
    }

    //  17 characters, three of which take two bytes in UTF-8.
    printf("characters: %d\n",CkStringBuilder_getLength(sbText));
    printf("bytes encoded: %d\n",CkJsonObject_IntOf(jsonOut,"symbols[0].payloadBytes"));
    printf("ECI header: %d\n",CkJsonObject_HasMember(jsonOut,"symbols[0].selectedEncoding.eci"));

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

    //  

    //  The same text with an ECI header declaring UTF-8.
    CkJsonObject_UpdateInt(json,"encoding.eci",26);
    CkJsonObject_UpdateString(json,"output.path","qa_output/qr_utf8_eci.png");
    success = CkFormats_QrCode(fmt,"generate",json,jsonOut);
    if (success == FALSE) {
        printf("%s\n",CkFormats_lastErrorText(fmt));
        CkStringBuilder_Dispose(sbText);
        CkJsonObject_Dispose(json);
        CkFormats_Dispose(fmt);
        CkJsonObject_Dispose(jsonOut);
        return;
    }

    printf("with encoding.eci = 26, ECI header: %d, value %d\n",CkJsonObject_HasMember(jsonOut,"symbols[0].selectedEncoding.eci"),CkJsonObject_IntOf(jsonOut,"symbols[0].selectedEncoding.eci"));

    //  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


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

    }