利用qt写一段获取json数据的代码

可以使用Qt自带的网络模块QNetworkAccessManager来获取json数据，示例代码如下：

#include <QCoreApplication>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>

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

    QNetworkAccessManager manager;
    QNetworkRequest request(QUrl("http://example.com/data.json"));
    QNetworkReply *reply = manager.get(request);

    QObject::connect(reply, &QNetworkReply::finished, [&](){
        QByteArray data = reply->readAll();
        QJsonDocument doc = QJsonDocument::fromJson(data);
        QJsonObject obj = doc.object();
        QJsonArray arr = obj["data"].toArray();
        for (int i = ; i < arr.size(); i++) {
            QJsonObject item = arr[i].toObject();
            QString name = item["name"].toString();
            int age = item["age"].toInt();
            qDebug() << "name:" << name << ", age:" << age;
        }
        reply->deleteLater();
        QCoreApplication::quit();
    });

    return a.exec();
}

以上代码会从"http://example.com/data.json"获取json数据，并解析其中的"data"数组，输出每个元素的"name"和"age"字段。