Day13QMainWindow2021-09-28

QMainWindow—— Use of the main window

The main window provides a framework for establishing the user interface of the application ,Qt Provides QMainWindow And some other related classes to complete the management of the main window .
menu bar ：QMenuBar, Contains a list of drop-down menu items , These menu items are controlled by QAction The action class implements . The menu bar is located at the top of the main window , A window can only have one menu bar .
The toolbar ：QToolBar, It is generally used to display some commonly used menu items , You can also insert other widgets , Button like .
Central part ： A window part can be placed in the central area of the main window as the central part , It is the area where the main functions of the application are realized .
Dock parts ：QDockWidget,Dock Parts are often referred to as docked windows , It is used to place some parts to realize functions , Similar toolbox .
status bar ： QStatusBar, Used to display some status information of the program , At the bottom of the main window .
These items can usually be added in the window through UI Interface operation , But in addition to the status bar . Specific functions usually need to be linked with code . The following example will add the above content to the form in pure code .
The code is as follows , The notes have been clearly described ：

    this->resize(600,400);
    /**************** menu bar   only one ***************/
    QMenuBar *bar=menuBar(); // This method is provided by the system , His return value is QMenuBar
    // Set the menu bar to the window 
    setMenuBar(bar);
    // Add menu  
    QMenu  *fileMenu=bar->addMenu(" file ");
    // Add menu item 
    QAction *newAction=fileMenu->addAction(" newly build ");
    // Add a split line 
    fileMenu->addSeparator();
     QAction *newAction1=fileMenu->addAction(" open ");

     /**************** The toolbar   Sure   There are many. ***************/
     QToolBar *toolBar = new QToolBar(this);
     // Put the toolbar in the window 
     addToolBar(Qt::LeftToolBarArea,toolBar);// The adjustment defaults to the left 
     // Only allowed to dock up and down 
     toolBar->setAllowedAreas(Qt::LeftToolBarArea|Qt::RightToolBarArea);
     // Floating is not allowed 
     toolBar->setFloatable(false);
     // Turn off mobile   Main switch 
     toolBar->setMovable(false);
     // Add gizmos to the toolbar 
     QPushButton *btn = new QPushButton(" Button ",this);
     toolBar->addWidget(btn);
     // Add menu item to toolbar 
     toolBar->addAction(newAction);
     // Add a split line 
     toolBar->addSeparator();
     toolBar->addAction(newAction1);

     /**************** status bar   only one ***************/
    QStatusBar *status = statusBar();
    // Add the status blue to the window 
    setStatusBar(status);

    // Put in the label 
    QLabel *label =new QLabel(" Left key information ",this);
    // Put the label in the status bar 
    status->addWidget(label);

    QLabel *label1 =new QLabel(" Right click information ",this);
    status->addPermanentWidget(label1);

    // Riveted parts   Floating window   There can be multiple 
    QDockWidget *dock = new QDockWidget(" Riveted parts ",this);
    addDockWidget(Qt::BottomDockWidgetArea,dock);
    // Set the docking range 
    dock->setAllowedAreas(Qt::TopDockWidgetArea|Qt::BottomDockWidgetArea);

    // Core components 
    QTextEdit *text = new QTextEdit(this);
    setCentralWidget(text);

The effect is as follows ：