Qt | C++ connect not being triggered

Question

I'm trying to play with basic signal/slot in C++.

Here is my Network-Manager, which will trigger the event:

class NetworkManager : public QObject {
Q_OBJECT
public:
    explicit NetworkManager(QApplication* application);
    void OnFinished(QNetworkReply *reply);
    ...
signals:
    void OnReceived();
};

And in Display-Manager, this class will receive the event:

class DisplayManager : public QObject{
Q_OBJECT
public:
    explicit DisplayManager(QApplication *app);
    void ChangeWallPaper();
public slots:
    void ReceiveData();
};

And I'm trying to connect from another class:

Manager::Manager(QApplication *application, NetworkManager networkManager, DisplayManager displayManager)
: networkManager(application),displayManager(application) {
    ...
    connect(&networkManager, &NetworkManager::OnReceived, &displayManager, &DisplayManager::ReceiveData);
}

And in these class's implementation:

void DisplayManager::ReceiveData() {
    std::cout << "being called" << std::endl;// to check if this is being called
}

void NetworkManager::OnFinished(QNetworkReply *reply) {
    OnReceived(); // to trigger
}
// OnReceived() not implemented as it just a signal

What am I missing here? Why is the ReceiveData function not being called?

Answer 1

Here is the solution :

Manager::Manager(QApplication *application,
                 NetworkManager _networkManager,
                 DisplayManager _displayManager)
        : networkManager(application)
        , displayManager(application)
{
    ...
    connect(&networkManager, &NetworkManager::OnReceived,
            &displayManager, &DisplayManager::ReceiveData);
}