如何覆盖QState并使用它

Question

我试图通过其子类覆盖onEntry和onExist上的QState函数。我该如何调用QState的构造函数。我对重新实现QState感到困惑。

class s : public QState
{
public:
    s(QState *parent = 0);
    ~s();
protected:
    void onEntry(QEvent *event) override;
    void onExit(QEvent *event);

};
void s::onEntry(QEvent *event)
{
    qDebug("on enter");
}

void s::onExit(QEvent *event)
{

}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    s * state = new s();
}

和QState就像：

class QState
{
protected:
     .
     .
public:
     void onEntry(QEvent *event);
     void onEntry(QEvent *event)
};