JSON传输数组的基本操作

目标JSON结果如下：

生成JSON的的过程如下：

Document document;
    Document::AllocatorType& allocator = document.GetAllocator();

    //根
    Value root(kObjectType);

    Value records(kArrayType);
    for (int i = 0;i< signlogList.size();i++)
    {
        Value record_info(kObjectType);
        record_info.SetObject();

        record_info.AddMember("id", signlogList[i].face_id, allocator);

        Value snapshot_time(kStringType);
        snapshot_time.SetString(signlogList[i].snapshot_time.c_str(), allocator);

        record_info.AddMember("recoTime", snapshot_time, allocator);

        Mat faceMat = imread(signlogList[i].snapshot_url);

        vector<uchar> buff;//buffer for coding
        vector<int> param = vector<int>(2);
        param[0]=CV_IMWRITE_JPEG_QUALITY;
        param[1]=95;//default(95) 0-100

        imencode(".jpg",faceMat,buff,param);
        char* imgData = new char[buff.size()];
        memset(imgData, 0, buff.size());
        for (int ii=0;ii < buff.size();ii++)
        {
            imgData[ii] = buff[ii];
        }

        std::string imgBase64="";
        CBase64::Encode((uchar*)imgData, buff.size(),imgBase64);

        delete[] imgData;
        imgData = NULL;

        Value pic(kStringType);

        pic.SetString(imgBase64.c_str(), allocator);

        record_info.AddMember("pic", pic, allocator);

        record_info.AddMember("sim", signlogList[i].score, allocator);

        records.PushBack(record_info, allocator);
    }

    root.AddMember("records", records, allocator);

    string strTime = get_current_datetime();

    Value sendTime(kStringType);
    sendTime.SetString(strTime.c_str(), allocator);

    root.AddMember("sendTime", sendTime, allocator);

    string strMD5 = Common::Utility::generate_md5(strTime+config_info_.tianyu_order.key);

    Value sign(kStringType);
    sign.SetString(strMD5.c_str(), allocator);

    root.AddMember("sign", sign, allocator);