Qt QMainWindow at Close

Question

this may seem like a very simple question, but I want to dump some data whenever the QMainWindow closes, so I used the following piece of code:

QObject::connect(MainWindow.centralwidget, SIGNAL(destroyed()), this, SLOT(close()));

But this doesn't seem to make it call close(). Am I doing this wrong?.
Isn't the centralwidget suppose to be destroyed?.

Or perhaps the application closes before close() can be called?.

Any other ways of doing it then?

Answer 1

You better to re implement one virtual function in your main MainWindow class like this:

class MainWindow : public QMainWindow {

    Q_OBJECT;

public:
    MainWindow();

protected:
     void closeEvent(QCloseEvent *event);
}

and then declare in source file:

void MainWindow::closeEvent(QCloseEvent *event) {
     // do some data saves or something else
}

Good luck.

Answer 2

I'd try QGuiApplication::lastWindowClosed() instead.

Answer 3

Could you implement the closeEvent function for your QMainWindow and put your code there?