#include <QtWidgets>

int main(int argc, char** argv)
{
    QApplication app(argc, argv);
    QMainWindow w;

    auto menu_e = w.menuBar()->addMenu("Enabled Menu");
    w.menuBar()->addMenu("Disabled Menu")->setDisabled(true);

    QIcon icon(":/qt_logo.png");
    menu_e->addAction(icon, "Enabled");
    menu_e->addAction(icon, "Disabled")->setDisabled(true);

    w.resize(300, 150);
    w.show();

    return app.exec();
}