问改变QPushButton数

EN

    #ifndef TICTACTOEWIDGET_H
#define TICTACTOEWIDGET_H

#include <QWidget>
class QPushButton;
class TicTacToeWidget : public QWidget
{
    Q_OBJECT

public:
    TicTacToeWidget(QWidget *parent = 0);
    ~TicTacToeWidget();
    int size()const;
    void resizeBoard(int m);
private:
    QList<QPushButton *> m_board;
    int m_size;
    void setupBoard(int m);
    void clearBoard();


};

#endif // TICTACTOEWIDGET_H

    #include "tictactoewidget.h"
#include <QMessageBox>
#include <QGridLayout>
#include <QPushButton>
#include <QDebug>
TicTacToeWidget::TicTacToeWidget(QWidget *parent)
    : QWidget(parent),m_size(3)
{
    setupBoard(3);
}

TicTacToeWidget::~TicTacToeWidget()
{

}

int TicTacToeWidget::size() const
{
    return m_size;
}

void TicTacToeWidget::resizeBoard(int m)
{
    setupBoard(m);
}

void TicTacToeWidget::setupBoard(int m)
{

    QGridLayout *gridLayout= new QGridLayout;
    m_size=m;
    m_board.clear();
    for(int i=0;i<m_size;i++)
    {
        for(int j=0;j<m_size;j++)
        {
            QPushButton *button= new QPushButton;
            button->setSizePolicy(QSizePolicy::Minimum,QSizePolicy::Minimum);
            button->setText(" ");
            gridLayout->addWidget(button,i,j);
        }
    }
    setLayout(gridLayout);

}

void TicTacToeWidget::clearBoard()
{
    for(auto &it:m_board)
    {
        this->layout()->removeWidget(it);
    }
    m_board.clear();

}

 #include "tictactoewidget.h"
    #include <QApplication>
    using namespace std;
    int main(int argc, char *argv[])
    {
        QApplication a(argc, argv);
        TicTacToeWidget w;
        w.resizeBoard(5);
        w.show();

        return a.exec();
    }