How to translate language in Qt on the fly

Question

I am using Translator and linguist to translate language in my application in Qt symbain, But I want to do this on the fly (on run time), I have tried the solution given by

Answer 1

The link you gave states:

However, the basic principle is to override QWidget::changeEvent() in every widget which has to be aware of dynamic language changes.

This is required as installTranslator() will create a change event which will be sent to every single widget. This means, if you want your MainWindow to be retranslated, you have to do:

void MainWindow::changeEvent(QEvent* event)
{
    if (event->type() == QEvent::LanguageChange)
    {
        // retranslate designer form (single inheritance approach)
        ui.retranslateUi(this);
    }

    // remember to call base class implementation
    QMainWindow::changeEvent(event);
}

You have to do this for every widget which has a translatable GUI

[Edit - Added comment as it was the actual answer to the question]

Don't call setLanguage() from within changeEvent()! You should call setLanguage() from wherever you can change the language. setLanguage() calls LanguageTranslator::loadTranslation() which calls QApplication::installTranslator() which creates a LanguageChange Event which is then caught in MainWindow::changeEvent