Qt读写Json

#include 

#include 
#include 
#include 

#include 

#include 

void writeJson() {

    QJsonObject rootObj;

    // 1. 插入 name 字段
    rootObj.insert("name", "China");

    // 2. 插入 info 字段
    QJsonObject infoObj;
    infoObj.insert("capital", "beijing");
    infoObj.insert("asian", true);
    infoObj.insert("founded", 1949);

    rootObj.insert("info", infoObj);


    // 3. 插入 provinces 字段
    QJsonArray provinceArray;

    QJsonObject provinceSdObj;
    provinceSdObj.insert("name", "shandong");
    provinceSdObj.insert("capital", "jinan");

    QJsonObject provinceZjObj;
    provinceZjObj.insert("name", "zhejiang");
    provinceZjObj.insert("capital", "hengzhou");

    provinceArray.append(provinceSdObj);
    provinceArray.append(provinceZjObj);

    rootObj.insert("provinces", provinceArray);

    // 4.将rootObj转换为json字符串
    QJsonDocument doc(rootObj);
    QByteArray json = doc.toJson();

    // 5.1 打印输出
    qDebug() << QString(json).toUtf8().data();

    // 5.2 将json字符串写入到文件
    QFile file("e:\\china.json");
    file.open(QFile::WriteOnly);
    file.write(json);
    file.close();
}

void fromJson() {

    // 1. 读取文件
    QFile file("e:\\china.json");
    file.open(QFile::ReadOnly);
    QByteArray json = file.readAll();
    file.close();

    QJsonDocument doc = QJsonDocument::fromJson(json);
    if(!doc.isObject()) {
        qDebug() << "Not an object!";
        return;
    }

   // 2. 开始解析
    QJsonObject obj = doc.object();
    QStringList keys = obj.keys();
    for(int i = 0; i < keys.size(); i++) {
        // 获取key-value
        QString key = keys[i];
        QJsonValue value = obj.value(key);

        if(value.isBool()) {
            //
            qDebug() << key << ":" << value.toBool();
        } else if (value.isString()) {
            qDebug() << key << ":" << value.toString();
        } else if (value.isDouble()) {
            qDebug() << key << ":" << value.toInt();
        } else if(value.isObject()) {
            qDebug() << key << ":";

            QJsonObject infoObj = value.toObject();
            QString capital = infoObj["capital"].toString();
            bool asian = infoObj["asian"].toBool();
            int founded = infoObj["founded"].toInt();

            qDebug() << "  " << "capital" << ":" << capital;
            qDebug() << "  " << "asian" << ":" << asian;
            qDebug() << "  " << "founded" << ":" << founded;
        } else if (value.isArray()) {
            qDebug() << key;

            QJsonArray provinceArray = value.toArray();

            for(int i = 0; i < provinceArray.size(); i++) {
                QJsonObject provinceObj = provinceArray[i].toObject();

                QString name = provinceObj["name"].toString();
                QString capital = provinceObj["capital"].toString();

                qDebug() << "  " << "name" << ":" << name << ", capital" << ":" << capital;
            }
        }
    }
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

//    writeJson();

    fromJson();

    return a.exec();
}