I can't use a function from C ++

[Mikeeeeee]

Hi.
I can't use a function from C ++.
Created a class:

class DataWorking : public QObject
{
public:
    DataWorking();
    ~DataWorking();
    Q_INVOKABLE  int randomNumber;
    int winNumber;
    int progressNumber;
    int roundNumber;// число раундов
 
public slots:
    Q_INVOKABLE  void setRandomNamber(int first, int last);
 
};

DataWorking::DataWorking()
{
    winNumber = 0;
    progressNumber = 0;
    roundNumber = 20;
}

DataWorking::~DataWorking()
{
    winNumber = 0;
    progressNumber = 0;
}

void DataWorking::setRandomNamber(int first, int last)
{
    //randomNumber = Random::get(first, last);
    randomNumber=654;
    qDebug()<<"randomNamber = "<<randomNumber;
}

main.cpp:

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;

    DataWorking dataWorking;

    QQmlContext *context = engine.rootContext();   
       context->setContextProperty("dataWorking", &dataWorking);

    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;

    return app.exec();
}

I specify connection in main.qml:

   Connections
     {
         target: dataWorking // Указываем целевое соединение
 
     }

and trying to call a class function:

   page1Button0.onClicked: //left button
    {
        dataWorking.setRandomNamber(1,55)
    }

but I get the error: Property 'setRandomNamber' of object QObject (0x22fd40) is not a function.
Tell me please, how can I use this function?

[KroMignon]

@Mikeeeeee said in I can't use a function from C ++:

DataWorking

I think you have to change the DataWorking constructor, to call QObject constructor, and very important add Q_OBJECT macro to enable QObject magic:

class DataWorking : public QObject
{
    Q_OBJECT
public:
    explicit DataWorking(QObject *parent = 0);
 ...

in cpp

DataWorking::DataWorking(QObject *parent) : QObject(parent)
{
    winNumber = 0;
    progressNumber = 0;
    roundNumber = 20;
}

Other remark, Q_INVOKABLE is only required if function is not a slot. slots are accessible from QML.