pTranslator->load(":/Resources/qt_ru.qm")

void MainWindow::create_language_menu()
{
    // Создаём меню языков
    QActionGroup *languageActionGroup = new QActionGroup(this);
    connect(languageActionGroup, SIGNAL(triggered(QAction *)), this, SLOT(switchLanguage(QAction *)));

    QDir dir(qmPath);
    QStringList fileNames = dir.entryList( QStringList("*.qm"));

    QString sellocale = "en";

    for (int i=0; i < fileNames.size(); i++)
    {
        QString locale = fileNames[i];
        locale.remove(0, locale.indexOf('_')+1);
        locale.truncate(locale.lastIndexOf('.'));

        QTranslator translator;
        translator.load(fileNames[i], qmPath);
        QString language = translator.translate("MainWindow", "English");

        QAction *action = new QAction(tr("%1").arg(language), this);
        action->setCheckable(true);
        action->setData(locale);        

        languageActionGroup->addAction(action);

        if (locale == sellocale)
        {
            switchLanguage(action);
            action->setChecked(true);
        }
    }
}