QMenuBar not displaying

[Saviz]

I am trying to create a simple QMenuBar with one QMenu.

mainwindow.h file:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QMenuBar>
#include <QMenu>

class MainWindow : public QMainWindow
{
// Macros
    Q_OBJECT

// Constructors
public:
    MainWindow(QWidget *parent = nullptr);

// Destructors
public:
    ~MainWindow();

// QWidgets
private:
    QWidget *QWidget_CenteralWidget;
    QMenuBar *QMenuBar_Bar;
    QMenu *QMenu_File;

// Methods
private:
    void setupGUI();
};

#endif

mainwindow.cpp file:

#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
{
    setupGUI();
}

MainWindow::~MainWindow()
{
}

mainwindow_gui.cpp file:

#include "mainwindow.h"

void MainWindow::setupGUI()
{
    // MainWindow
    if (this->objectName().isEmpty())
    {
        this->setObjectName(QString::fromUtf8("QMainWindow_MainWindow"));
    }

    this->setWindowState(Qt::WindowMaximized);


    // Centeral Widget
    QWidget_CenteralWidget = new QWidget(this);

    QWidget_CenteralWidget->setStyleSheet("background-color: gray;");

    this->setCentralWidget(QWidget_CenteralWidget);


    // QMenuBar
    QMenuBar_Bar = new QMenuBar(this);
    QMenuBar_Bar->setVisible(true);
    QMenuBar_Bar->setStyleSheet("background-color: red;");

    QMenu_File = new QMenu(QMenuBar_Bar);
    QMenu_File->setObjectName(

                QString::fromUtf8("QMenu_File")
                );


    QMenuBar_Bar->addMenu(QMenu_File);

    this->setMenuBar(QMenuBar_Bar);
}

Here is the output:

As you can see, the menu bar is nowhere to be found.

Why is this happening?

[Chris Kawa]

Your menu has no text, so it occupies no space. Give it something to show e.g.

QMenu_File = new QMenu("&File", QMenuBar_Bar);
QMenuBar_Bar->addMenu(QMenu_File);

or a shorthand:

QMenu_File = QMenuBar_Bar->addMenu("&File");

Btw. setObjectName has an overload that takes QAnyStringView, so you can use it and save on dynamically allocating temporary QString: setObjectName("QMainWindow_MainWindow").

Btw.2 Calling this->setWindowState(Qt::WindowMaximized);or any other variant of show() in the constructor is a bad practice. A widget should not dictate how it is shown. This should be the responsibility of the code that creates it. It would also make calling QMenuBar_Bar->setVisible(true); unnecessary, as it would be shown automatically when the parent is shown.

[Saviz]

@Chris-Kawa Thank you for your solutions and suggestions. I made sure to use the overload and to change my code to use the following in the appropriate place:

this->setWindowState(Qt::WindowMaximized);

Thank you again.