内容

• 特性
• 公共函数
• 重实现公共函数
• 公共槽
• 信号
• 保护函数
• 重实现保护函数
• 详细描述
• 用法
• 从属平台的外观和感觉
• QMenuBar 作为全局菜单栏
• 范例

QMenuBar 类

QMenuBar class provides a horizontal menu bar. 更多...

头：	#include <QMenuBar>
qmake:	QT += widgets
继承：	QWidget

• 所有成员列表，包括继承成员

特性

• defaultUp : bool
• nativeMenuBar : bool

• 59 特性继承自 QWidget
• 1 特性继承自 QObject

公共函数

	QMenuBar (QWidget * parent = Q_NULLPTR)
	~QMenuBar ()
QAction *	actionAt (const QPoint & pt ) const
QRect	actionGeometry (QAction * act ) const
QAction *	activeAction () const
QAction *	addAction (const QString & text )
QAction *	addAction (const QString & text , const QObject * receiver , const char * member )
QAction *	addMenu (QMenu * menu )
QMenu *	addMenu (const QString & title )
QMenu *	addMenu (const QIcon & icon , const QString & title )
QAction *	addSeparator ()
void	clear ()
QWidget *	cornerWidget (Qt::Corner corner = Qt::TopRightCorner) const
QAction *	insertMenu (QAction * before , QMenu * menu )
QAction *	insertSeparator (QAction * before )
bool	isDefaultUp () const
bool	isNativeMenuBar () const
void	setActiveAction (QAction * act )
void	setCornerWidget (QWidget * widget , Qt::Corner corner = Qt::TopRightCorner)
void	setDefaultUp ( bool )
void	setNativeMenuBar (bool nativeMenuBar )
NSMenu *	toNSMenu ()

重实现公共函数

virtual int	heightForWidth ( int ) const override
virtual QSize	minimumSizeHint () const override
virtual QSize	sizeHint () const override

• 214 公共函数继承自 QWidget
• 32 公共函数继承自 QObject
• 14 公共函数继承自 QPaintDevice

公共槽

virtual void

setVisible (bool visible ) override

• 19 公共槽继承自 QWidget
• 1 公共槽继承自 QObject

信号

void	hovered (QAction * action )
void	triggered (QAction * action )

• 3 信号继承自 QWidget
• 2 信号继承自 QObject

保护函数

void	initStyleOption (QStyleOptionMenuItem * option , const QAction * action ) const

重实现保护函数

virtual void	actionEvent (QActionEvent * e ) override
virtual void	changeEvent (QEvent * e ) override
virtual bool	event (QEvent * e ) override
virtual bool	eventFilter (QObject * object , QEvent * event ) override
virtual void	focusInEvent ( QFocusEvent * ) override
virtual void	focusOutEvent ( QFocusEvent * ) override
virtual void	keyPressEvent (QKeyEvent * e ) override
virtual void	leaveEvent ( QEvent * ) override
virtual void	mouseMoveEvent (QMouseEvent * e ) override
virtual void	mousePressEvent (QMouseEvent * e ) override
virtual void	mouseReleaseEvent (QMouseEvent * e ) override
virtual void	paintEvent (QPaintEvent * e ) override
virtual void	resizeEvent ( QResizeEvent * ) override
virtual void	timerEvent (QTimerEvent * e ) override

• 35 保护函数继承自 QWidget
• 9 保护函数继承自 QObject
• 1 保护函数继承自 QPaintDevice

额外继承成员

• 5 静态公共成员继承自 QWidget
• 11 静态公共成员继承自 QObject
• 1 保护槽继承自 QWidget

详细描述

QMenuBar class provides a horizontal menu bar.

菜单栏由下拉菜单项列表组成。添加菜单项采用 addMenu ()。例如，假定 menubar 是指针指向 QMenuBar and fileMenu 是指针指向 QMenu ，以下语句将菜单插入菜单栏：

menubar->addMenu(fileMenu);
					

The ampersand in the menu item's text sets Alt+F as a shortcut for this menu. (You can use "&&" to get a real ampersand in the menu bar.)

There is no need to lay out a menu bar. It automatically sets its own geometry to the top of the parent widget and changes it appropriately whenever the parent is resized.

用法

In most main window style applications you would use the menuBar() function provided in QMainWindow , adding QMenu s to the menu bar and adding QAction s to the pop-up menus.

范例 (来自 菜单 范例)：

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

菜单项可以被移除采用 removeAction ().

Widgets can be added to menus by using instances of the QWidgetAction class to hold them. These actions can then be inserted into menus in the usual way; see the QMenu 文档编制了解更多细节。

从属平台的外观和感觉

Different platforms have different requirements for the appearance of menu bars and their behavior when the user interacts with them. For example, Windows systems are often configured so that the underlined character mnemonics that indicate keyboard shortcuts for items in the menu bar are only shown when the Alt key is pressed.

QMenuBar 作为全局菜单栏

On macOS and on certain Linux desktop environments such as Ubuntu Unity, QMenuBar is a wrapper for using the system-wide menu bar. If you have multiple menu bars in one dialog the outermost menu bar (normally inside a widget with widget flag Qt::Window ) will be used for the system-wide menu bar.

Qt for macOS also provides a menu bar merging feature to make QMenuBar conform more closely to accepted macOS menu bar layout. The merging functionality is based on string matching the title of a QMenu entry. These strings are translated (using QObject::tr ()) in the " QMenuBar " context. If an entry is moved its slots will still fire as if it was in the original place. The table below outlines the strings looked for and where the entry is placed if matched:

String matches	Placement	注意事项
about.*	Application Menu | About <application name>	The application name is fetched from the Info.plist file (see note below). If this entry is not found no About item will appear in the Application Menu.
config, options, setup, settings or preferences	Application Menu | Preferences	If this entry is not found the Settings item will be disabled
quit or exit	Application Menu | Quit <application name>	If this entry is not found a default Quit item will be created to call QCoreApplication::quit ()

You can override this behavior by using the QAction::menuRole () property.

If you want all windows in a Mac application to share one menu bar, you must create a menu bar that does not have a parent. Create a parent-less menu bar this way:

QMenuBar *menuBar = new QMenuBar(0);
					

注意： Do not call QMainWindow::menuBar () to create the shared menu bar, because that menu bar will have the QMainWindow as its parent. That menu bar would only be displayed for the parent QMainWindow .

注意： The text used for the application name in the macOS menu bar is obtained from the value set in the Info.plist file in the application's bundle. See Qt for macOS - 部署 了解更多信息。

注意： On Linux, if the com.canonical.AppMenu.Registrar service is available on the D-Bus session bus, then Qt will communicate with it to install the application's menus into the global menu bar, as described.

范例

菜单 范例展示如何使用 QMenuBar and QMenu 。其它 主窗口应用程序范例 还提供使用这些类的菜单。

另请参阅 QMenu , QShortcut , QAction , Apple 人机界面指南介绍 , GUI 设计手册：菜单栏 ，和 菜单范例 .

特性文档编制

defaultUp : bool

此特性保持弹出取向

The default popup orientation. By default, menus pop "down" the screen. By setting the property to true, the menu will pop "up". You might call this for menus that are below the document to which they refer.

If the menu would not fit on the screen, the other direction is used automatically.

访问函数：

bool	isDefaultUp () const
void	setDefaultUp ( bool )

nativeMenuBar : bool

This property holds whether or not a menubar will be used as a native menubar on platforms that support it

This property specifies whether or not the menubar should be used as a native menubar on platforms that support it. The currently supported platforms are macOS, and Linux desktops which use the com.canonical.dbusmenu D-Bus interface (such as Ubuntu Unity). If this property is true , the menubar is used in the native menubar and is not in the window of its parent; if false the menubar remains in the window. On other platforms, setting this attribute has no effect, and reading this attribute will always return false .

The default is to follow whether the Qt::AA_DontUseNativeMenuBar attribute is set for the application. Explicitly setting this property overrides the presence (or absence) of the attribute.

该特性在 Qt 4.6 引入。

访问函数：

bool	isNativeMenuBar () const
void	setNativeMenuBar (bool nativeMenuBar )

成员函数文档编制

QMenuBar:: QMenuBar ( QWidget * parent = Q_NULLPTR)

构造菜单栏采用父级 parent .

QMenuBar:: ~QMenuBar ()

销毁菜单栏。

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

返回 QAction at pt . Returns 0 if there is no action at pt 或者若位置拥有分隔符。

另请参阅 addAction () 和 addSeparator ().

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

重实现自 QWidget::actionEvent ().

QRect QMenuBar:: actionGeometry ( QAction * act ) const

返回几何体对于动作 act 作为 QRect .

另请参阅 actionAt ().

QAction *QMenuBar:: activeAction () const

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

另请参阅 setActiveAction ().

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

这是重载函数。

此方便函数创建新动作，采用 text 。函数将新近创建的动作添加到菜单的动作列表，并返回它。

另请参阅 QWidget::addAction () 和 QWidget::actions ().

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

这是重载函数。

此方便函数创建新动作采用给定 text 。动作的 triggered () 信号被连接到 receiver 's member slot. The function adds the newly created action to the menu's list of actions and returns it.

另请参阅 QWidget::addAction () 和 QWidget::actions ().

QAction *QMenuBar:: addMenu ( QMenu * menu )

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

注意： 返回的 QAction 对象可以用于隐藏相应菜单。

另请参阅 QWidget::addAction () 和 QMenu::menuAction ().

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

追加新的 QMenu with title to the menu bar. The menu bar takes ownership of the menu. Returns the new menu.

另请参阅 QWidget::addAction () 和 QMenu::menuAction ().

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

追加新的 QMenu with icon and title to the menu bar. The menu bar takes ownership of the menu. Returns the new menu.

另请参阅 QWidget::addAction () 和 QMenu::menuAction ().

QAction *QMenuBar:: addSeparator ()

将分隔符追加到菜单。

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

重实现自 QWidget::changeEvent ().

void QMenuBar:: clear ()

从菜单栏移除所有动作。

注意： 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.

另请参阅 removeAction ().

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

返回第一菜单项左侧或最后菜单项右侧 Widget，从属 corner .

注意： 使用角落除了 Qt::TopRightCorner or Qt::TopLeftCorner 将导致警告。

另请参阅 setCornerWidget ().

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

重实现自 QObject::event ().

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

重实现自 QObject::eventFilter ().

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

重实现自 QWidget::focusInEvent ().

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

重实现自 QWidget::focusOutEvent ().

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

重实现自 QWidget::heightForWidth ().

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

此信号被发射当突显菜单动作时； action 是导致事件被发送的动作。

这经常被用于更新状态信息。

另请参阅 triggered () 和 QAction::hovered ().

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

初始化 option 采用的值来自菜单栏和信息来自 action 。此方法对子类是有用的，当需要 QStyleOptionMenuItem ，但不希望自己填充所有信息。

另请参阅 QStyleOption::initFrom () 和 QMenu::initStyleOption ().

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

此方便函数插入 menu 先于动作 before 并返回菜单 menuAction()。

另请参阅 QWidget::insertAction () 和 addMenu ().

QAction *QMenuBar:: insertSeparator ( QAction * before )

此方便函数创建新分隔符动作，即：动作采用 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.

另请参阅 QWidget::insertAction () 和 addSeparator ().

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

重实现自 QWidget::keyPressEvent ().

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

重实现自 QWidget::leaveEvent ().

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

重实现自 QWidget::minimumSizeHint ().

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

重实现自 QWidget::mouseMoveEvent ().

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

重实现自 QWidget::mousePressEvent ().

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

重实现自 QWidget::mouseReleaseEvent ().

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

重实现自 QWidget::paintEvent ().

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

重实现自 QWidget::resizeEvent ().

void QMenuBar:: setActiveAction ( QAction * act )

把目前突显动作设为 act .

该函数在 Qt 4.1 引入。

另请参阅 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.

注意： 使用角落除了 Qt::TopRightCorner or Qt::TopLeftCorner 将导致警告。

另请参阅 cornerWidget ().

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

重实现自 QWidget::setVisible ().

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

重实现自 QWidget::sizeHint ().

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

重实现自 QObject::timerEvent ().

NSMenu *QMenuBar:: toNSMenu ()

返回此菜单栏的本机 NSMenu。只可用于 macOS。

注意： 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.

该函数在 Qt 5.2 引入。

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

此信号被发射当属于此菜单栏的菜单动作被触发作为鼠标点击结果时； action 是导致信号被发射的动作。

注意： QMenuBar 必须拥有所有权对于 QMenu 为使此信号工作。

通常，连接每个菜单动作到单个槽使用 QAction::triggered ()，但有时想要将几项连接到单个槽 (最常见，若用户从数组中选择)。此信号在这种情况下很有用。

另请参阅 hovered () 和 QAction::triggered ().