(Qt 5.7.0)如何在toolBar中添加水平间隔符

#include <QtWidgets>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QMainWindow mainWindow;
    QToolBar *toolBar = new QToolBar("My Toolbar", &mainWindow);
    mainWindow.addToolBar(toolBar);

    // 添加工具按钮
    QAction *action1 = new QAction(QIcon(":/icons/icon1.png"), "Action 1", &mainWindow);
    QAction *action2 = new QAction(QIcon(":/icons/icon2.png"), "Action 2", &mainWindow);
    toolBar->addAction(action1);
    toolBar->addAction(action2);

    // 添加水平间隔符
    toolBar->addSeparator();

    // 添加更多工具按钮
    QAction *action3 = new QAction(QIcon(":/icons/icon3.png"), "Action 3", &mainWindow);
    QAction *action4 = new QAction(QIcon(":/icons/icon4.png"), "Action 4", &mainWindow);
    toolBar->addAction(action3);
    toolBar->addAction(action4);

    mainWindow.show();

    return app.exec();
}