MQTT 订阅范例

// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QTcpSocket>
#include <QtMqtt/QMqttClient>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
public slots:
    void setClientPort(int p);
private slots:
    void on_buttonConnect_clicked();
    void on_buttonQuit_clicked();
    void updateLogStateChange();
    void brokerDisconnected();
    void on_buttonPublish_clicked();
    void on_buttonSubscribe_clicked();
private:
    Ui::MainWindow *ui;
    QMqttClient *m_client;
};
#endif // MAINWINDOW_H