Sample code for 30+ languages & platforms
C++

QR Code Generator via api.qrserver.com REST API

See more HTTP Examples

Demonstrates how to generate a QR code using the api.qrserver.com REST API service.

Chilkat C++ Downloads

C++
#include <CkHttp.h>
#include <CkJsonObject.h>
#include <CkHttpResponse.h>
#include <CkBinData.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.

    CkHttp http;

    //  Send the following GET request to get a binary response.
    //  The body of the binary response contains the image data for the QR code.
    //  https://api.qrserver.com/v1/create-qr-code/?data=[URL-encoded-text]&size=[pixels]x[pixels]

    CkJsonObject queryParams;
    queryParams.UpdateString("data","Hello World");
    queryParams.UpdateString("size","100x100");

    //  Get a PNG file..
    //  Possible formats are:
    //  png
    //  gif
    //  jpeg
    //  jpg
    //  svg
    //  eps
    //  Case matters.  Use lowercase.
    queryParams.UpdateString("format","png");

    //  Send the GET request to an endpoint.
    //  Chilkat will add the url-encoded query params passed in the JSON.
    CkHttpResponse resp;
    success = http.HttpParams("GET","https://api.qrserver.com/v1/create-qr-code/",queryParams,resp);
    if (success == false) {
        std::cout << http.lastErrorText() << "\r\n";
        return;
    }

    //  Did it succeed?
    if (resp.get_StatusCode() != 200) {
        //  The response body, if anything, would not be the image data, but would likely be the error text (or HTML, or whatever...)
        std::cout << resp.bodyStr() << "\r\n";
        std::cout << "Response status = " << resp.get_StatusCode() << "\r\n";
        std::cout << "Failed." << "\r\n";
        return;
    }

    //  Success if we get here..
    //  Save the binary body as the PNG file, or you can get the bytes of the PNG..
    success = resp.SaveBodyBinary("c:/temp/qa_output/qr_code.png");

    //  Or get the bytes:
    CkBinData bd;
    resp.GetBodyBd(bd);
    //  Use the bytes in bd...
    //  See the online reference documentation for the function to access the bytes directly.

    std::cout << "Success." << "\r\n";
    }