Qmainwindow details

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QMainWindow What is it? ？

QMainWindow Is a class that provides the main window program for users , Contains a menu bar （menu bar）、 Multiple toolbars (tool bars)、 Multiple anchoring components (dock widgets)、 A status bar (status bar) And a central part (central widget), Is the foundation of many applications , Like a text editor , Picture editor, etc .

1. menu bar

A main window has at most one menu bar . At the top of the main window 、 Under the title bar of the main window .

1. Create menu bar , adopt QMainWindow Class menubar（） Function to get the main window menu bar pointer

QMenuBar *	menuBar() const

2. Create a menu , call QMenu Member function of addMenu To add a menu

QAction* addMenu(QMenu * menu)
QMenu* addMenu(const QString & title)
QMenu* addMenu(const QIcon & icon, const QString & title)

3. Create menu items , call QMenu Member function of addAction To add menu items

QAction* activeAction() const
QAction* addAction(const QString & text)
QAction* addAction(const QIcon & icon, const QString & text)
QAction* addAction(const QString & text, const QObject * receiver,const char * member, const QKeySequence & shortcut = 0)
QAction* addAction(const QIcon & icon, const QString & text, const QObject * receiver, const char * member, const QKeySequence & shortcut = 0)

Qt There is no special menu item class , Just use a QAction class , Abstract public actions . When we put QAction Object to add to menu , It's displayed as a menu item , Add to toolbar , It shows up as a tool button . The user can click on the menu item 、 Click the toolbar button 、 Click the shortcut to activate the action .

2. The toolbar

There can be more than one toolbar in the main window , Usually, a menu corresponds to a toolbar , You can also divide the toolbar according to your needs .

Call directly QMainWindow Class addToolBar（） Function to get the toolbar object of the main window , You need to call this function once every time you add a toolbar .

Insert actions that belong to the toolbar , That is to add an operation on the toolbar . adopt QToolBar Class addAction Function add .

The toolbar is a movable window , Its docking area is made up of QToolBar Of allowAreas decision , Include ：

Qt::LeftToolBarArea		// Stop on the left side 
Qt::RightToolBarArea		// Stop on the right side 
Qt::TopToolBarArea		// Stop at the top 
Qt::BottomToolBarArea   	// Dock at the bottom 
Qt::AllToolBarAreas		// The above four positions can be docked 

Use setAllowedAreas（） Function to specify the docking area ：

setAllowedAreas（Qt::LeftToolBarArea | Qt::RightToolBarArea）

Use setMoveable（） Function to set the mobility of the toolbar ：

setMoveable（false）// The toolbar is not removable ,  It can only be docked at the initialization position 

3. status bar

Derive from QWidget class , Usage and QWidget similar ,QStatusBar Class common member functions ：

The status bar can only have at most one

// Add a widget 
void addWidget(QWidget * widget, int stretch = 0)
// Insert the widget 
int	insertWidget(int index, QWidget * widget, int stretch = 0)
// Delete widget 
void removeWidget(QWidget * widget)

4. Riveted parts

Riveted parts QDockWidget, Also known as floating window , There can be multiple .

QDockWidget * dock = new QDockWidget(" title ",this);
addDockWidget(Qt::LeftDockWidgetArea,dock);
dock->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea | Qt::TopDockWidgetArea);  // Set the area range 

5. Core components （ Central part ）

In addition to the above parts , All the components displayed in the center can be used as core components , For example, a notepad file , You can use QTextEdit Make the core components

QTextEdit * edit = new QTextEdit(this);
setCentralWidget(edit);