QT is the most basic layout, creating a window interface

#include "mainwindow.h"

#include <QMenuBar>
#include <QToolBar>
#include <QStatusBar>
#include <QLabel>
#include <QDockWidget>
#include <QTextEdit>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    

    resize(400,300);

    QMenuBar *menubar = new QMenuBar(this);
    setMenuBar(menubar);

    QMenu *filename = menubar->addMenu(" file ");
    QMenu *editmenu = menubar->addMenu(" edit ");
    QMenu *buildname = menubar->addMenu(" structure ");

    filename->addAction(" New file ");
    filename->addAction(" Open file ");
    filename->addSeparator();
    filename->addAction(" Close file ");

    editmenu->addAction(" recovery ");
    buildname->addAction(" Build all projects ");

    // ToolBar
    QToolBar *toolbar = new QToolBar(this);
    addToolBar(Qt::TopToolBarArea, toolbar);
    toolbar->addAction(" newly build ");
    toolbar->addSeparator();
    toolbar->addAction(" open ");
    toolbar->addSeparator();
    toolbar->addAction(" close ");

    // statusbar
    QStatusBar *statusbar = new QStatusBar(this);
    setStatusBar(statusbar);

    QLabel *label = new QLabel(this);
    label->setText(" status bar ");
    statusbar->addWidget(label);


    // DockWidgets  Floating window   Docking window   Docking position of the central part 
    //  verification ： Whether the floating window is on the left side of the central part 
    QDockWidget *dockWidget = new QDockWidget(" A small window ", this);
    addDockWidget(Qt::LeftDockWidgetArea, dockWidget);

    // Center Widget  Text editor or browser section 
    QTextEdit *edit = new QTextEdit(this);
    setCentralWidget(edit);

}

MainWindow::~MainWindow()
{
    
}