c++qtstatic-membersqapplicationqcoreapplication

Please instantiate the QApplication object first

I have a static class and want it to have static QSettings. But with my initialization I get a warning:

QSettings* MySQLConnection::settings = new QSettings(QApplication::applicationDirPath() + "/config.ini", QSettings::IniFormat);

QCoreApplication::applicationDirPath: Please instantiate the QApplication object first

As a workaround I initialize the QSetting manually at the beginning of my main function. Is there any better way to initialize my static member?

Thank you!

Solution

  • Ideally, you should have no static class instances of any sort. Singletons should have a local instance in main() and their static methods should forward through an instance pointer to regular methods. See how QCoraApplication does it for a good example.

    In any case, a QSettings instance can be ephemeral. It's only a handle to the settings mechanism. Not much point in making it static or keeping it around. It's normal to have QSettings as a local variable in a function.