在QDialog中添加了QMenuBar，它显示但子菜单无法打开

Question

我使用Designer中设置的布局在QDialog中添加了QMenuBar，然后手动添加QMenuBar。当运行应用程序和QDialog时，我看到的QMenuBar只有菜单标题，没有打开的子菜单：
这是我的代码：
这是设计器生成的头文件：

QT_BEGIN_NAMESPACE
class Ui_AutoDialog
{
public:
    QVBoxLayout *verticalLayout;
    QWidget *widget_menuBarHolder;
    QVBoxLayout *verticalLayout_2;
    QVBoxLayout *verticalLayout_menuBarLayOut;
    QWebView *webView;
    QWidget *widget;
    void setupUi(QDialog *AutoDialog)
    {
        if (AutoDialog->objectName().isEmpty())
            AutoDialog->setObjectName(QString::fromUtf8("AutoDialog"));
        AutoDialog->resize(436, 365);
        verticalLayout = new QVBoxLayout(AutoDialog);
        verticalLayout->setSpacing(0);
        verticalLayout->setContentsMargins(0, 0, 0, 0);
        verticalLayout->setObjectName(QString::fromUtf8("verticalLayout"));
        widget_menuBarHolder = new QWidget(AutoDialog);
        widget_menuBarHolder->setObjectName(QString::fromUtf8("widget_menuBarHolder"));
        widget_menuBarHolder->setMinimumSize(QSize(0, 20));
        verticalLayout_2 = new QVBoxLayout(widget_menuBarHolder);
        verticalLayout_2->setSpacing(0);
        verticalLayout_2->setContentsMargins(0, 0, 0, 0);
        verticalLayout_2->setObjectName(QString::fromUtf8("verticalLayout_2"));
        verticalLayout_menuBarLayOut = new QVBoxLayout();
        verticalLayout_menuBarLayOut->setSpacing(0);
        verticalLayout_menuBarLayOut->setObjectName(QString::fromUtf8("verticalLayout_menuBarLayOut"));
        verticalLayout_2->addLayout(verticalLayout_menuBarLayOut);

        verticalLayout->addWidget(widget_menuBarHolder);
        webView = new QWebView(AutoDialog);
        webView->setObjectName(QString::fromUtf8("webView"));
        webView->setUrl(QUrl("about:blank"));
        verticalLayout->addWidget(webView);
        widget = new QWidget(AutoDialog);
        widget->setObjectName(QString::fromUtf8("widget"));
        widget->setMinimumSize(QSize(0, 20));
        verticalLayout->addWidget(widget);

        retranslateUi(AutoDialog);
        QMetaObject::connectSlotsByName(AutoDialog);
    } // setupUi
    void retranslateUi(QDialog *AutoDialog)
    {
        AutoDialog->setWindowTitle(QApplication::translate("AutoDialog", "Dialog", 0, QApplication::UnicodeUTF8));
    } // retranslateUi
};
namespace Ui {
    class AutoDialog: public Ui_AutoDialog {};
} // namespace Ui
QT_END_NAMESPACE

这是QDialog构造函数，它是构建QMenuBAr:的部分

ui.setupUi(this);
    /*ui.verticalLayout_menuBarLayOut->addWidget(SetMenuBar());
    ui.verticalLayout_menuBarLayOut->setMargin(0);
    ui.verticalLayout_menuBarLayOut->setSpacing(0);*/
    m_actionClose = new QAction(this);
    m_actionClose->setObjectName(QString::fromUtf8("actionClose"));
    m_actionPreferences = new QAction(this);
    m_actionPreferences->setObjectName(QString::fromUtf8("actionPreferences"));
    m_menubar = new QMenuBar(this);
    m_menubar->setObjectName(QString::fromUtf8("menubar"));
    m_menubar->setGeometry(QRect(0, 0, 314, 18));
    m_menuFile = new QMenu(m_menubar);
    m_menuFile->setObjectName(QString::fromUtf8("menuFile"));
    m_menuSettings = new QMenu(m_menubar);
    m_menuSettings->setObjectName(QString::fromUtf8("menuSettings"));
    m_menubar->setMinimumSize(QSize(0, 20));
    ui.verticalLayout_menuBarLayOut->setMenuBar(m_menubar);
    m_menubar->addAction(m_menuFile->menuAction());
    m_menubar->addAction(m_menuSettings->menuAction());
    m_menuFile->addSeparator();
    m_menuFile->addAction(m_actionClose);
    m_menuSettings->addAction(m_actionPreferences);
    m_actionClose->setText(QApplication::translate("MainWindow", "Close", 0, QApplication::UnicodeUTF8));
    m_actionPreferences->setText(QApplication::translate("MainWindow", "Preferences", 0, QApplication::UnicodeUTF8));
    m_menuFile->setTitle(QApplication::translate("MainWindow", "File", 0, QApplication::UnicodeUTF8));
    m_menuSettings->setTitle(QApplication::translate("MainWindow", "Settings", 0, QApplication::UnicodeUTF8));


    bar = new QStatusBar(this);
    bar->setMinimumSize(QSize(0, 20));
    ui.verticalLayout->removeWidget(ui.widget);
    ui.verticalLayout->addWidget(bar);
    ui.verticalLayout->setMargin(0);
    ui.verticalLayout->setSpacing(0);

    pb = new QProgressBar(bar);
    pb->setTextVisible(false);
    pb->hide();
    bar->addPermanentWidget(pb);

这里出了什么问题，为什么我看不到子菜单。。关闭&偏好？

Answer 1

我不熟悉添加菜单的方式，因为我通常以不同的方式将菜单添加到菜单栏中。

尝试

m_menubar->addMenu( m_menuFile );
m_menubar->addMenu( m_menuSettings );

而不是

m_menubar->addAction(m_menuFile->menuAction());
m_menubar->addAction(m_menuSettings->menuAction());

让我知道这是否有效。如果没有，我一定会调查另一个问题。