快速 MQTT 范例

// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#ifndef QMLMQTTCLIENT_H
#define QMLMQTTCLIENT_H
#include <QtCore/QMap>
#include <QtMqtt/QMqttClient>
#include <QtMqtt/QMqttSubscription>
class QmlMqttClient;
class QmlMqttSubscription : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QMqttTopicFilter topic MEMBER m_topic NOTIFY topicChanged)
public:
    QmlMqttSubscription(QMqttSubscription *s, QmlMqttClient *c);
    ~QmlMqttSubscription();
Q_SIGNALS:
    void topicChanged(QString);
    void messageReceived(const QString &msg);
public slots:
    void handleMessage(const QMqttMessage &qmsg);
private:
    Q_DISABLE_COPY(QmlMqttSubscription)
    QMqttSubscription *sub;
    QmlMqttClient *client;
    QMqttTopicFilter m_topic;
};
class QmlMqttClient : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QString hostname READ hostname WRITE setHostname NOTIFY hostnameChanged)
    Q_PROPERTY(int port READ port WRITE setPort NOTIFY portChanged)
    Q_PROPERTY(QMqttClient::ClientState state READ state WRITE setState NOTIFY stateChanged)
public:
    QmlMqttClient(QObject *parent = nullptr);
    Q_INVOKABLE void connectToHost();
    Q_INVOKABLE void disconnectFromHost();
    Q_INVOKABLE QmlMqttSubscription *subscribe(const QString &topic);
    const QString hostname() const;
    void setHostname(const QString &newHostname);
    int port() const;
    void setPort(int newPort);
    const QMqttClient::ClientState state() const;
    void setState(const QMqttClient::ClientState &newState);
signals:
    void hostnameChanged();
    void portChanged();
    void stateChanged();
private:
    Q_DISABLE_COPY(QmlMqttClient)
    QMqttClient m_client;
};
#endif // QMLMQTTCLIENT_H