删除QMenu和QToolBar之间的白色分隔符

Question

我在Qt写过QMenu和QToolBar。 这就是我得到的：

我无法找到任何方法在QMenu（文件，编辑）和QToolBar（带钢琴图标的两个按钮）之间删除此白色分隔符。

代码：

MainWindow::MainWindow()
{

    this->setStyleSheet("background-color: black;");
    initMenu();
    initButtons();

}

void MainWindow::initMenu()
{

    menuBar()->setStyleSheet("background: #555555; "
                             "color: #EEEEEE; "
                             "selection-background-color: #222222; "
                             "border-color:#EEEEEE;");

    QMenu *fileMenu = menuBar()->addMenu("File");

    QAction *newFileAction = new QAction("New", this);
    newFileAction->setShortcut(QKeySequence::New);
    newFileAction->setStatusTip("Create new file.");
    //connect
    fileMenu->addAction(newFileAction);

    QAction *openFileAction = new QAction("Open", this);
    openFileAction->setShortcut(QKeySequence::Open);
    openFileAction->setStatusTip("Open file.");
    //connect
    fileMenu->addAction(openFileAction);

    QAction *saveFileAction = new QAction("Save", this);
    saveFileAction->setShortcut(QKeySequence::Save);
    saveFileAction->setStatusTip("Save file.");
    //connect
    fileMenu->addAction(saveFileAction);

    QAction *saveAsFileAction = new QAction("Save as", this);
    saveAsFileAction->setShortcut(QKeySequence::SaveAs);
    saveAsFileAction->setStatusTip("Save file as another file.");
    //connect
    fileMenu->addAction(saveAsFileAction);

    fileMenu->addSeparator();

    QAction *quitAction = new QAction("Quit", this);
    quitAction->setShortcut(QKeySequence::Quit);
    quitAction->setStatusTip("Quit program.");
    //connect
    fileMenu->addAction(quitAction);

    QMenu *editMenu = menuBar()->addMenu("Edit");
    QAction *copyAction = new QAction("Copy", this);
    copyAction->setShortcut(QKeySequence::Copy);
    copyAction->setStatusTip("Copy.");
    //connect
    editMenu->addAction(copyAction);

}

void MainWindow::initButtons()
{


    QToolBar *buttonToolBar = addToolBar("Buttons");
    buttonToolBar->setStyleSheet("background: #555555");
    buttonToolBar->setMovable(false);

    const QIcon pianoIcon = QIcon::fromTheme("piano-roll",QIcon(":/buttons/b_piano.png"));
    QAction *pianoAction = new QAction(pianoIcon, tr("&Piano Roll"), this);
    pianoAction->setShortcut(QKeySequence(Qt::CTRL + Qt::Key_1));
    pianoAction->setStatusTip("Opens Piano Roll window.");
    //connect();
    buttonToolBar->addAction(pianoAction);

    const QIcon piano2Icon = QIcon::fromTheme("piano-roll2",QIcon(":/buttons/i_piano.png"));
    QAction *piano2Action = new QAction(piano2Icon, tr("&Piano Roll"), this);
    piano2Action->setShortcut(QKeySequence(Qt::CTRL + Qt::Key_2));
    piano2Action->setStatusTip("Opens Piano Roll window number two.");
    //connect();
    buttonToolBar->addAction(piano2Action);
}

在MainWindow中我运行了两个函数。第一个功能创建了Qmenu。第二个用两个按钮创建QToolBar。