QMenuBar Class

  menubar->addMenu(fileMenu);

      fileMenu = menuBar()->addMenu(tr("&File"));
      fileMenu->addAction(newAct);

  QMenuBar *menuBar = new QMenuBar(0);

成员函数

QMenuBar::QMenuBar(QWidget *parent = Q_NULLPTR)

Constructs a menu bar with parent parent.

QMenuBar::~QMenuBar()

Destroys the menu bar.

QAction *QMenuBar::actionAt(const QPoint &pt) const

Returns the QAction at pt. Returns 0 if there is no action at pt or if the location has a separator.

参见 addAction() and addSeparator().

[override virtual protected] void QMenuBar::actionEvent(QActionEvent *e)

重新实现 QWidget::actionEvent().

QRect QMenuBar::actionGeometry(QAction *act) const

Returns the geometry of action act as a QRect.

参见 actionAt().

QAction *QMenuBar::activeAction() const

Returns the QAction that is currently highlighted. A null pointer will be returned if no action is currently selected.

参见 setActiveAction().

QAction *QMenuBar::addAction(const QString &text)

This is an overloaded function.

This convenience function creates a new action with text. The function adds the newly created action to the menu's list of actions, and returns it.

参见 QWidget::addAction() and QWidget::actions().

QAction *QMenuBar::addAction(const QString &text, const QObject *receiver, const char *member)

This is an overloaded function.

This convenience function creates a new action with the given text. The action's triggered() signal is connected to the receiver's member slot. The function adds the newly created action to the menu's list of actions and returns it.

参见 QWidget::addAction() and QWidget::actions().

QAction *QMenuBar::addMenu(QMenu *menu)

Appends menu to the menu bar. Returns the menu's menuAction().

Note: The returned QAction object can be used to hide the corresponding menu.

参见 QWidget::addAction() and QMenu::menuAction().

QMenu *QMenuBar::addMenu(const QString &title)

Appends a new QMenu with title to the menu bar. The menu bar takes ownership of the menu. Returns the new menu.

参见 QWidget::addAction() and QMenu::menuAction().

QMenu *QMenuBar::addMenu(const QIcon &icon, const QString &title)

Appends a new QMenu with icon and title to the menu bar. The menu bar takes ownership of the menu. Returns the new menu.

参见 QWidget::addAction() and QMenu::menuAction().

QAction *QMenuBar::addSeparator()

Appends a separator to the menu.

[override virtual protected] void QMenuBar::changeEvent(QEvent *e)

重新实现 QWidget::changeEvent().

void QMenuBar::clear()

Removes all the actions from the menu bar.

Note: On macOS, menu items that have been merged to the system menu bar are not removed by this function. One way to handle this would be to remove the extra actions yourself. You can set the menu role on the different menus, so that you know ahead of time which menu items get merged and which do not. Then decide what to recreate or remove yourself.

参见 removeAction().

QWidget *QMenuBar::cornerWidget(Qt::Corner corner = Qt::TopRightCorner) const

Returns the widget on the left of the first or on the right of the last menu item, depending on corner.

Note: Using a corner other than Qt::TopRightCorner or Qt::TopLeftCorner will result in a warning.

参见 setCornerWidget().

[override virtual protected] bool QMenuBar::event(QEvent *e)

重新实现 QObject::event().

[override virtual protected] bool QMenuBar::eventFilter(QObject *object, QEvent *event)

重新实现 QObject::eventFilter().

[override virtual protected] void QMenuBar::focusInEvent(QFocusEvent *)

重新实现 QWidget::focusInEvent().

[override virtual protected] void QMenuBar::focusOutEvent(QFocusEvent *)

重新实现 QWidget::focusOutEvent().

[override virtual] int QMenuBar::heightForWidth(int) const

重新实现 QWidget::heightForWidth().

[signal] void QMenuBar::hovered(QAction *action)

This signal is emitted when a menu action is highlighted; action is the action that caused the event to be sent.

Often this is used to update status information.

参见 triggered() and QAction::hovered().

[protected] void QMenuBar::initStyleOption(QStyleOptionMenuItem *option, const QAction *action) const

Initialize option with the values from the menu bar and information from action. This method is useful for subclasses when they need a QStyleOptionMenuItem, but don't want to fill in all the information themselves.

参见 QStyleOption::initFrom() and QMenu::initStyleOption().

QAction *QMenuBar::insertMenu(QAction *before, QMenu *menu)

This convenience function inserts menu before action before and returns the menus menuAction().

参见 QWidget::insertAction() and addMenu().

QAction *QMenuBar::insertSeparator(QAction *before)

This convenience function creates a new separator action, i.e. an action with QAction::isSeparator() returning true. The function inserts the newly created action into this menu bar's list of actions before action before and returns it.

参见 QWidget::insertAction() and addSeparator().

[override virtual protected] void QMenuBar::keyPressEvent(QKeyEvent *e)

重新实现 QWidget::keyPressEvent().

[override virtual protected] void QMenuBar::leaveEvent(QEvent *)

重新实现 QWidget::leaveEvent().

[override virtual] QSize QMenuBar::minimumSizeHint() const

重新实现 QWidget::minimumSizeHint().

[override virtual protected] void QMenuBar::mouseMoveEvent(QMouseEvent *e)

重新实现 QWidget::mouseMoveEvent().

[override virtual protected] void QMenuBar::mousePressEvent(QMouseEvent *e)

重新实现 QWidget::mousePressEvent().

[override virtual protected] void QMenuBar::mouseReleaseEvent(QMouseEvent *e)

重新实现 QWidget::mouseReleaseEvent().

[override virtual protected] void QMenuBar::paintEvent(QPaintEvent *e)

重新实现 QWidget::paintEvent().

[override virtual protected] void QMenuBar::resizeEvent(QResizeEvent *)

重新实现 QWidget::resizeEvent().

void QMenuBar::setActiveAction(QAction *act)

Sets the currently highlighted action to act.

This function was introduced in Qt 4.1.

参见 activeAction().

void QMenuBar::setCornerWidget(QWidget *widget, Qt::Corner corner = Qt::TopRightCorner)

This sets the given widget to be shown directly on the left of the first menu item, or on the right of the last menu item, depending on corner.

The menu bar takes ownership of widget, reparenting it into the menu bar. However, if the corner already contains a widget, this previous widget will no longer be managed and will still be a visible child of the menu bar.

Note: Using a corner other than Qt::TopRightCorner or Qt::TopLeftCorner will result in a warning.

参见 cornerWidget().

[override virtual slot] void QMenuBar::setVisible(bool visible)

重新实现 QWidget::setVisible().

[override virtual] QSize QMenuBar::sizeHint() const

重新实现 QWidget::sizeHint().

[override virtual protected] void QMenuBar::timerEvent(QTimerEvent *e)

重新实现 QObject::timerEvent().

NSMenu *QMenuBar::toNSMenu()

Returns the native NSMenu for this menu bar. Available on macOS only.

Note: Qt may set the delegate on the native menu bar. If you need to set your own delegate, make sure you save the original one and forward any calls to it.

This function was introduced in Qt 5.2.

[signal] void QMenuBar::triggered(QAction *action)

This signal is emitted when an action in a menu belonging to this menubar is triggered as a result of a mouse click; action is the action that caused the signal to be emitted.

Note: QMenuBar has to have ownership of the QMenu in order this signal to work.

Normally, you connect each menu action to a single slot using QAction::triggered(), but sometimes you will want to connect several items to a single slot (most often if the user selects from an array). This signal is useful in such cases.

参见 hovered() and QAction::triggered().