QT实现点击按钮切换窗口

//firstwidget.h
#ifndef FIRSTWIDGET_H
#define FIRSTWIDGET_H

#include 
#include 
#include 
class FirstWidget : public QWidget
{
    Q_OBJECT

public:
    FirstWidget(QWidget *parent = nullptr);
    ~FirstWidget();
    void myhide();
    void hide_2();

private:
    QPushButton b1;
    secondwidget w2;

};
#endif // FIRSTWIDGET_H

//firstwidget.cpp
#include "firstwidget.h"
#include "secondwidget.h"
FirstWidget::FirstWidget(QWidget *parent)
    : QWidget(parent)
{
    b1.setParent(this);
    b1.setText("切换到窗口2");
    w2.setWindowTitle("窗口2");
    connect(&b1,&QPushButton::released,this,&FirstWidget::myhide);
   connect(&w2,&secondwidget::mySignal,this,&FirstWidget::hide_2);
}
void FirstWidget::myhide()
{
    this->hide();
    w2.show();
}
void FirstWidget::hide_2()
{

    this->show();
    w2.hide();
}
FirstWidget::~FirstWidget()
{
}

//secondwidget.h
#ifndef SECONDWIDGET_H
#define SECONDWIDGET_H

#include 
#include 
class secondwidget : public QWidget
{
    Q_OBJECT
public:
    explicit secondwidget(QWidget *parent = nullptr);
    void sendSolt();

signals:
    void mySignal();
private:
    QPushButton b2;


};

#endif // SECONDWIDGET_H

//seconndwidget.cpp
#include "secondwidget.h"

secondwidget::secondwidget(QWidget *parent) : QWidget(parent)
{
    b2.setParent(this);
    b2.setText("切换到窗口1");
    connect(&b2,&QPushButton::clicked,this,&secondwidget::sendSolt);

}
void secondwidget::sendSolt()
{
    emit mySignal();
}