mosquitto_sub -h 192.168.0.137 -t "house" -v

-h 是指定从哪个服务器订阅；

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五、软件测试 

 

 

 

测试结果：

 

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六、QT使用MQTT 

   6.1 MQTT初始化

    6.1.1 源码下载

 

    6.2.1 将源码添加到工程 

 

添加到network模块

 

   

   6.3.1 添加头文件路径 

出错：解决方法

 

 6.4.1 编译

 

出错

解决方法：

 

  6.5.1 mqtt初始化 

QMQTT::Client *mqttClient ;
QString clientID;
qsrand(QTime(0,0,0).msecsTo(QTime::currentTime()));
clientID = "XYD-CXX"+QString::number(qrand()); //合成 mqtt id
//mqtt 初始化
mqttClient = new QMQTT::Client(ui->lEditServerIP->text(), 1883);
mqttClient->setClientId(clientID); //ClientId 不能重复，不然会覆盖之前连接的人的
//mqttClient->setUsername("user"); //服务器账号密码，不需要则不用
//mqttClient->setPassword("password");
mqttClient->connect();

  6.6.1mqtt信号与槽

//mqtt 连接成功
connect(mqttClient,SIGNAL(connected()),this,SLOT(doProcessMqttConnected()));
//mqtt 退出成功 
connect(mqttClient,SIGNAL(disconnected()),this,SLOT(doProcessMqttDisconnected()));
//mqtt 订阅成功 
connect(mqttClient,SIGNAL(subscribed(QString)),this,SLOT(doProcessMqttSubscribe(QSt
ring)));
//mqtt 订阅到消息 
connect(mqttClient,SIGNAL(received(QMQTT::Message)),this,SLOT(doProcessMqttReceived
(QMQTT::Message)));

   6.7.1 MQTT发布

if(mqttIsConnected)
{
 QMQTT::Message msg;
 msg.setTopic(ui->lEditPub->text()); //发布的主题
//发布的内容,QString 转 QByteArray
 msg.setPayload(ui->lEditPubPayload->text().toLatin1());
mqttClient->publish(msg);
}

   订阅成功的槽函数：一般不用这个

void MqttForm::doProcessMqttSubscribe(QString topic)
{
 //qDebug()<< topic + "is Subscribe";
}

收到信息的槽函数：

void MqttForm::doProcessMqttReceived(QMQTT::Message msg)
{
qDebug() << "topic:" + msg.topic();
qDebug() << "payload:" + msg.payload();
}