当我向time API发出请求以获取莫斯科时间时,我在变量中得到了空的int
这是代码:

QNetworkReply* reply = manager->get(QNetworkRequest(QUrl("https://yandex.com/time/sync.json?geo=213")));
QEventLoop loop;
connect(reply, &QNetworkReply::finished, &loop, &QEventLoop::quit);
loop.exec();

QByteArray data = reply->readAll();
QJsonDocument document = QJsonDocument::fromJson(data);
QJsonObject root = document.object();
qDebug() << data;
qDebug() << root.value("time").toInt();

这是JSON:
{"time":1519489796585,"clocks":{"213":{"id":213,"name":"Moscow","offset":10800000,"offsetString":"UTC+3:00","showSunriseSunset":true,"sunrise":"07:33","sunset":"17:53","isNight":true,"skyColor":"#3f68b2","weather":{"temp":-10,"icon":"ovc","link":"/moscow"},"parents":[{"id":225,"name":"Russia"}]}}}

最佳答案

如果将数字修改为:1519490351963,则该值超过整数的较大值:2147483647,因此无法转换为整数,可能的解决方案是将其转换为 double :

// qDebug() << root["time"].toDouble();
qDebug() << root.value("time").toDouble();

另一种可能的解决方案是将其转换为QVariant,然后使用toLongLong()使用qlonglong,它是一种支持更多位的整数类型。
//qDebug() << root["time"].toVariant().toLongLong();
qDebug() << root.value("time").toVariant().toLongLong();

关于c++ - QJsonValue为空,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/48965090/

10-10 17:37