Unicode C++ Requires Chilkat v11.7.0+

Generate a QR Code PNG in Memory

See more QR Code Examples

Demonstrates getting a QR code image without writing a file. With no output options the result is a PNG returned as base64 in outputs[0].base64 of the response. The example decodes it into a BinData, which holds the bytes of the PNG to send in an HTTP response, store in a database, attach to an email, or save. Unicode C++

#include <CkJsonObjectW.h>
#include <CkFormatsW.h>
#include <CkBinDataW.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/");
    json.UpdateInt(L"render.moduleSize",6);

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

    wprintf(L"format: %s\n",jsonOut.stringOf(L"outputs[0].format"));
    wprintf(L"MIME type: %s\n",jsonOut.stringOf(L"outputs[0].mimeType"));
    wprintf(L"image: %d x %d pixels\n",jsonOut.IntOf(L"outputs[0].width"),jsonOut.IntOf(L"outputs[0].height"));

    //  outputs[0].base64 is the PNG file, base64 encoded.
    CkBinDataW bdPng;
    success = bdPng.AppendEncoded(jsonOut.stringOf(L"outputs[0].base64"),L"base64");
    if (success == false) {
        wprintf(L"%s\n",bdPng.lastErrorText());
        return;
    }

    wprintf(L"PNG bytes: %d\n",bdPng.get_NumBytes());

    //  The BinData holds the image.  Here it is simply saved.
    success = bdPng.WriteFile(L"qa_output/qr_in_memory.png");
    if (success == false) {
        wprintf(L"%s\n",bdPng.lastErrorText());
        return;
    }

    //  The PNG held in bdPng:

    //  

    //  Sample output:

    //  format: png
    //  MIME type: image/png
    //  image: 222 x 222 pixels
    //  PNG bytes: 877
    }