使用Visual Studio 2022调用libqrencode生成二维码

新建一个VS控制台新项目qrtest

建立项目后建立主程序文件，拷贝qrencode.h到工程目录，配置依赖qrencode.lib。

代码

void qr_code(std::string _src_str, std::string _dst_bmp_path)
{
    const char* szSourceSring = _src_str.c_str();
    unsigned int unWidth, x, y, l, n, unWidthAdjusted, unDataBytes;
    unsigned char* pRGBData, * pSourceData, * pDestData;
    QRcode* pQRC;
    FILE* f;

    if (pQRC = QRcode_encodeString(szSourceSring, 0, QR_ECLEVEL_H, QR_MODE_8, 1))
    {
        unWidth = pQRC->width;
        unWidthAdjusted = unWidth * 8 * 3;
        if (unWidthAdjusted % 4) {
            unWidthAdjusted = (unWidthAdjusted / 4 + 1) * 4;
        }
        unDataBytes = unWidthAdjusted * unWidth * 8;
        if (!(pRGBData = (unsigned char*)malloc(unDataBytes))) {
            std::cout << "malloc err" << std::endl;
            exit(-1);
        }

        //Preset to White
        memset(pRGBData, 0xff, unDataBytes);

        //Prepare bmp headers
        BITMAPFILEHEADER kFileHeader;
        kFileHeader.bfType = 0x4d42;    //"BM"
        kFileHeader.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + unDataBytes;
        kFileHeader.bfReserved1 = 0;
        kFileHeader.bfReserved2 = 0;
        kFileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
        BITMAPINFOHEADER kInfoHeader;
        kInfoHeader.biSize = sizeof(BITMAPINFOHEADER);
        kInfoHeader.biWidth = unWidth * 8;
        kInfoHeader.biHeight = ((int)unWidth * 8);
        kInfoHeader.biPlanes = 1;
        kInfoHeader.biBitCount = 24;
        kInfoHeader.biCompression = BI_RGB;
        kInfoHeader.biSizeImage = 0;
        kInfoHeader.biXPelsPerMeter = 0;
        kInfoHeader.biYPelsPerMeter = 0;
        kInfoHeader.biClrUsed = 0;
        kInfoHeader.biClrImportant = 0;

        //Convert QrCode bits to bmp pixels
        pSourceData = pQRC->data;
        for (y = 0; y < unWidth; y++)
        {
            pDestData = pRGBData + unWidthAdjusted * y * 8;
            for (x = 0; x < unWidth; x++)
            {
                if (*pSourceData & 1)
                {
                    for (l = 0; l < 8; l++)
                    {
                        for (n = 0; n < 8; n++)
                        {
                            //以下三行是设置三基色 三基色设置0x00 则二维码颜色就是黑色的
                            *(pDestData + n * 3 + unWidthAdjusted * l) = 0xff;
                            *(pDestData + 1 + n * 3 + unWidthAdjusted * l) = 0x00;
                            *(pDestData + 2 + n * 3 + unWidthAdjusted * l) = 0x00;
                        }
                    }
                }
                pDestData += 3 * 8;
                pSourceData++;
            }
        }

        //output the bmp file
        if (!(fopen_s(&f, _dst_bmp_path.c_str(), "wb")))
        {
            fwrite(&kFileHeader, sizeof(BITMAPFILEHEADER), 1, f);
            fwrite(&kInfoHeader, sizeof(BITMAPINFOHEADER), 1, f);
            fwrite(pRGBData, sizeof(unsigned char), unDataBytes, f);
            std::cout << "qrcode has generated in " << _dst_bmp_path.c_str() << std::endl;
            fclose(f);
        }
        else
        {
            std::cout << "unable to open file" << std::endl;
            exit(-1);
        }
        //Free data
        free(pRGBData);
        QRcode_free(pQRC);

    }
    else
    {
        std::cout << "NULL returned" << std::endl;
        exit(-1);
    }
}

调用

// TODO: 在此添加控件通知处理程序代码
    std::string _src_str = "http://www.baidu.com";
    std::string _dst_bmp_path = "2.png";
    qr_code(_src_str, _dst_bmp_path);

运行结果：