QT在课堂上打开一个新窗口

Question

所以我现在尝试制作一个益智游戏，当我点击Playbutton时会打开一个新窗口，从按钮接收SIGNAL打开SLOT函数openNewWindow如下所示：

部首：

class PuzzleField : public QPushButton{
signals: ....
public:  ....
private: ....
public slots:
    void openNewWindow();
}

CPP：

void PuzzleField::openNewWindow(){
    gui = new QWidget();
    gui->resize(400,200);
    std::vector<int> numbersLeft;
    for (int i = 0; i<= (this->height*this->width)-1; i++){
        numbersLeft.push_back(i);
    }
    auto engine = std::default_random_engine{};
    std::shuffle(std::begin(numbersLeft), std::end(numbersLeft), engine);
    QGridLayout *grid = new QGridLayout(gui);
    grid->setHorizontalSpacing(0);
    grid->setContentsMargins(0,0,0,0);
    grid->setVerticalSpacing(0);
    for (int h = 0; h < this->height; h++){
      for (int wi = 0; wi <this->width; wi++){
         QPushButton *btn = new 
         QPushButton(QString::number(numbersLeft.back()),gui);
         btn->resize(50,50);
         grid->addWidget(btn,h,wi);
         numbersLeft.pop_back();
      }
    }
    gui->setLayout(grid);
    gui->show();
}

我试图像这样打开窗口：

QWidget *game = new QWidget();
QPushButton *playButton = new QPushButton("Play");
 QObject::connect(playButton,SIGNAL(clicked()),game,SLOT(PuzzleField::openNewWindow()));

但单击按钮后窗口无法打开。也许我只是愚蠢，但我无法找到解决方案。

当只调用没有Signal / slot的功能时，一切正常，只需按下按钮然后打开窗口就不起作用了。

提前感谢您的帮助。