slot callback is invalid about examples HOT 2 CLOSED

#[derive(Debug)]
struct MainWindow {
    transText: Rc<TransText>,
    optLine: Rc<OptLine>,
}

pub fn startQt() {
    QApplication::init(|_| unsafe {
        let mainWindow = QMainWindow::new_0a();
        let windowWidget = QWidget::new_1a(&mainWindow);

        // I declared a variable in here, but not used
        let _mw = initWindowWidgets(&windowWidget);

        mainWindow.set_fixed_size_2a(700, 200);
        windowWidget.resize_1a(&mainWindow.size());
        mainWindow.set_window_title(&qs("Youdao Dict"));
        mainWindow.show();
        QApplication::exec()
    })
}


unsafe fn initWindowWidgets(windowWidget: &QBox<QWidget>) -> Rc<MainWindow> {
    let vBox = QVBoxLayout::new_1a(windowWidget);
    vBox.set_contents_margins_4a(0, 0, 0, 0);
    vBox.set_spacing(2);
    vBox.set_direction(Direction::Down);
    

    //初始化输入框
    let transText = TransText::new(&vBox);
    
    //初始化操作栏
    let _optLine = OptLine::new(&vBox, &transText);

    let mw = Rc::new(MainWindow{
        transText: transText,
        optLine: _optLine
    });
    mw
}