如何将菜单栏添加到QWidget？

Question

I am currently writing a C++ Application using the Qt framework, in which the 'main window' inherits from the QWidget class:

class Draughts : public QWidget
{
    Q_OBJECT
public:
    explicit Draughts(QWidget *parent = 0);
    ~Draughts();

private:
    Ui::Draughts *ui;
};

And I attempted to add a simple menu bar to the application, using the following code:

Draughts::Draughts(QWidget *parent) :

    QWidget(parent),
    ui(new Ui::Draughts)
{
    ui->setupUi(this);

    QWidget *menuWidget = new QWidget;

    QMenu *menuGame = new QMenu("Game");
    menuGame->addAction("New");
    menuGame->addAction("Exit");

    QMenu *menuHelp = new QMenu("Help");
    menuHelp->addAction("How to Play...");
    menuHelp->addAction("About");

    //Setup the Application Menu
    QMenuBar mainMenu(this);
    mainMenu.addMenu(menuGame);
    mainMenu.addMenu(menuHelp);
}

Should I be using the QMainWindow class instead of the QWidget class for my application?

Answer 1

It would be easier to use QMainWindow , because it provides a convenient menuBar() method:

QMenuBar* mainMenu = this->menuBar();

But it is possible to add it to QWidget , just as any other widget. Just don't allocate it in the local scope, because it will be deleted after the function finishes. Instead, do it like with other widgets:

QMenuBar mainMenu = new QMenuBar(this);

You should also probably add a layout to your widget, and add the menu to the layout to have more control over where does it appear. You may find this tutorial useful.