C++ 函式如何透過封裝程式碼來提高 GUI 開發的效率？

#include 

class MyWindow : public QMainWindow {
public:
    MyWindow() {
        QWidget *widget = new QWidget;
        setCentralWidget(widget);

        QVBoxLayout *layout = new QVBoxLayout;
        widget->setLayout(layout);

        QPushButton *showButton = new QPushButton("Show");
        QPushButton *hideButton = new QPushButton("Hide");
        QLabel *label = new QLabel("Hello, world!");
        label->setVisible(false);

        layout->addWidget(showButton);
        layout->addWidget(hideButton);
        layout->addWidget(label);

        connect(showButton, &QPushButton::clicked, this, &MyWindow::showLabel);
        connect(hideButton, &QPushButton::clicked, this, &MyWindow::hideLabel);
    }

private slots:
    void showLabel() {
        label->setVisible(true);
    }

    void hideLabel() {
        label->setVisible(false);
    }
};

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);
    MyWindow window;
    window.show();
    return app.exec();
}