QT MQTT 示例代码
时间: 2023-11-28 18:32:45 浏览: 70
当然,下面是一个使用QT框架和MQTT协议的示例代码:
```cpp
#include <QtWidgets/QApplication>
#include <QtWidgets/QMessageBox>
#include <QMQTT/Client>
#include <QMQTT/Message>
class MqttClient : public QObject
{
Q_OBJECT
public:
explicit MqttClient(const QString& host, quint16 port, QObject *parent = nullptr)
: QObject(parent), m_client(host, port)
{
connect(&m_client, &QMQTT::Client::connected, this, &MqttClient::onConnected);
connect(&m_client, &QMQTT::Client::disconnected, this, &MqttClient::onDisconnected);
connect(&m_client, &QMQTT::Client::received, this, &MqttClient::onMessageReceived);
m_client.setClientId("mqtt_example");
m_client.connectToHost();
}
public slots:
void onConnected()
{
qDebug() << "Connected to MQTT broker";
m_client.subscribe("my_topic");
}
void onDisconnected()
{
qDebug() << "Disconnected from MQTT broker";
QApplication::quit();
}
void onMessageReceived(const QMQTT::Message& message)
{
qDebug() << "Received message:" << message.payload();
}
private:
QMQTT::Client m_client;
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MqttClient mqttClient("mqtt.example.com", 1883);
return a.exec();
}
#include "main.moc"
```
请注意,这只是一个简单的示例代码,并不包含完整的错误处理和异常情况处理。你需要根据自己的需求进行适当的修改和扩展。此示例使用了QMQTT库,你需要在项目中添加该库的依赖项。
在这个示例中,我们创建了一个MqttClient类来处理MQTT连接和消息。在构造函数中,我们实例化了一个QMQTT::Client对象并连接到指定的MQTT代理服务器。在连接成功后,我们订阅了一个名为"my_topic"的主题。收到消息后,会在控制台输出消息内容。当与MQTT代理服务器断开连接时,会退出应用程序。
希望这个示例对你有帮助!