[大数据]Qt_Json

今天又要用Json文件了，留个笔记方便日后查看

void MainWindow::ReadFile() {
    //打开文件
    QVector<Time> Data = {};
    Time t_Data;
    QString fileName = "D://my.json";
    QFile file(fileName);
    QFile loadFile(fileName);
    if (!loadFile.open(QIODevice::ReadOnly)) {
        return;
    }
    //读取内容并转换为Json文件
    QByteArray allData = loadFile.readAll();
    loadFile.close();
    QJsonParseError jsonerror;
    QJsonDocument jsonDoc(QJsonDocument::fromJson(allData, &jsonerror));
    if (jsonerror.error != QJsonParseError::NoError) {
        return;
    }
    QJsonObject Obj1 = jsonDoc.object();
    QJsonObject Obj2 = jsonDoc.object();
    QJsonObject Obj3 = jsonDoc.object();
    for (int i = 0; i < Obj1.keys().size(); i++) {
        QJsonObject Obj2 = Obj1.value(Obj1.keys().at(i)).toObject();
        if(Obj2.keys().size() != 24) {
            return;
        }
        for(int j = 0; j < Obj2.keys().size(); j++) {
            QJsonObject Obj3 = Obj2.value(Obj2.keys().at(j)).toObject();
            t_Data.HeighTime = Obj3["HeighTime"].toInt();
            t_Data.MediumTime = Obj3["MediumTime"].toInt();
            t_Data.LowTime = Obj3["LowTime"].toInt();
            t_Data.NoTime = Obj3["NoTime"].toInt();
            Data.append(t_Data);
        }
    }
    for(int i = 0; i < Data.size(); i++) {
        qDebug() << i << Data[i].HeighTime << Data[i].LowTime << Data[i].MediumTime << Data[i].NoTime;
    }
}

void MainWindow::WriteFile() {
    QJsonObject jsonData, jsonHour, obj1;
    QDate date = QDate::currentDate();
    QString dateStr = date.toString("yyyy-M-d");
    for (int i = 0; i < 24; i++) {
        QString HourStr = QString("Data%1").arg(i);
        QString dataStr = date.toString("yyyy-M-d");
        obj1["HeighTime"] = 5;
        obj1["MediumTime"] = 6;
        obj1["LowTime"] = 8;
        obj1["NoTime"] = 6;
        jsonHour[HourStr] = obj1;
    }
    jsonData[dateStr] = jsonHour;
    QString fileName = "D://my.json";
    QFile file(fileName);
    // make a backup record
    QFileInfo fi(fileName);
    QString backupFileName = fi.absolutePath() + "/record_backup.json";
    if (file.exists()) {
        if (QFile::exists(backupFileName)) {
            QFile::remove(backupFileName);
        }
        QFile::copy(fileName, backupFileName);
    }
    if (!file.open(QIODevice::WriteOnly)) {
        return;
    }
    QJsonDocument jsonDoc(jsonData);
    //clear file content
    file.resize(0);
    file.write(jsonDoc.toJson());
    file.flush();
    file.close();
}