在开源QT中安装MQTT模块

sudo apt-get update
sudo apt-get install libmosquitto-dev

wget https://repo.eclipse.org/content/repositories/paho-releases/org/eclipse/paho/org.eclipse.paho.client.mqttv3/1.2.5/org.eclipse.paho.client.mqttv3-1.2.5.tar.gz
tar -xzf org.eclipse.paho.client.mqttv3-1.2.5.tar.gz
cd org.eclipse.paho.client.mqttv3-1.2.5
make
sudo make install

LIBS += -L/usr/local/lib -lmosquitto
INCLUDEPATH += /usr/local/include/mosquitto

#include <QCoreApplication>
#include <QTimer>
#include <iostream>
#include <mosquitto.h>

class MqttClient : public QObject {
    Q_OBJECT
public:
    MqttClient(const QString &host, int port, const QString &clientId) {
        mosqpp::lib_init();
        client = new mosqpp::client(clientId.toStdString().c_str());
        client->connect(host.toStdString().c_str(), port, 60);
        client->loop_start();
    }

    ~MqttClient() {
        client->loop_stop();
        delete client;
        mosqpp::lib_cleanup();
    }

    void publish(const QString &topic, const QString &message) {
        client->publish(topic.toStdString().c_str(), message.toStdString().c_str());
    }

private:
    mosqpp::client *client;
};

int main(int argc, char *argv[]) {
    QCoreApplication app(argc, argv);

    MqttClient mqttClient("localhost", 1883, "qt_mqtt_client");

    QTimer::singleShot(1000, [&]() {
        mqttClient.publish("test/topic", "Hello MQTT");
    });

    return app.exec();
}

#include "main.moc"