// mysingal.h
#ifndef MYSINGAL_H
#define MYSINGAL_H

#include <QObject>

class MySingal : public QObject
{
    Q_OBJECT
public:
    explicit MySingal(QObject *parent = nullptr) : QObject(parent) { }

signals:
    void TextSingal(int n);
public slots:
};

#endif // MYSINGAL_H

// myslot.h
#ifndef MYSLOT_H
#define MYSLOT_H

#include <QObject>

class MySlot : public QObject
{
    Q_OBJECT
public:
    explicit MySlot(QObject *parent = nullptr) : QObject(parent) { }

signals:

public slots:
};

#endif // MYSLOT_H

// mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QPushButton>

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
private:
    bool bAttach = false;
private:
    QPushButton* CreateBtn(const QString& btnName, const QSize& sz);
    void Close(const QString& btnName, const QSize& sz);
    void Switch(const QString& btnName, const QSize& sz, int n);
};
#endif // MAINWINDOW_H

// mainwindow.cpp
#include "mainwindow.h"
#include <QPushButton>
#include "mysingal.h"
#include "myslot.h"
#include <QDebug>


MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    setFixedSize(600, 400);
    Close("关闭", { 50, 50 });
    Switch("输出", { 150, 50 }, 10);
}

MainWindow::~MainWindow()
{
}

QPushButton* MainWindow::CreateBtn(const QString &btnName, const QSize& sz)
{
    if(btnName.toUtf8().data() == nullptr) return nullptr;
    QPushButton* btn = new QPushButton(btnName, this);
    if(!btn) return nullptr;
    btn->move(sz.width(), sz.height());
    btn->show();
    return btn;
}

void MainWindow::Close(const QString& btnName, const QSize& sz)
{
    QPushButton* btn = CreateBtn(btnName, sz);
    connect(btn, &QPushButton::clicked, this, [this]() {
        qDebug() << "CLose my window\n";
        close();
    });
}

void MainWindow::Switch(const QString& btnName, const QSize& sz, int n)
{
    QPushButton* btn = CreateBtn(btnName, sz);
    MySingal* pSingal = new MySingal(this);
    if(!pSingal) return;
    // 将输出按钮与信号关联, 需要捕获this的成员bAttach, 信号对象的地址, 信号函数的参数, 无需传参
    connect(btn, &QPushButton::clicked, this, [this, pSingal, n] () mutable {
        if(!bAttach) // bAttach为false 按钮无需关联信号函数
        {
            qDebug() << "*************";
            qDebug() << "信号与槽断开连接";
            qDebug() << "*************";
        }
        else        // 否则, 发送信号
        {
            qDebug() << "*************";
            qDebug() << "信号发送有参信号";
            emit pSingal->TextSingal(n);
        }
        bAttach = !bAttach; // 反转关联变量的值
    });
    MySlot* mySlot = new MySlot(this);
    if(!mySlot) return;
    // 关联信号与槽, 只需传递参数
    connect(pSingal, &MySingal::TextSingal, mySlot, [] (int n) mutable {
        qDebug() << "槽函数接收到有参信号: " << n;
        qDebug() << "*************";
    });
}

// main.cpp
#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}