计算MQTT连接参数。

调用MqttSign.cs中的MqttSign计算MQTT连接参数。String productKey = "a1X2bEn****";

String deviceName = "example1";

String deviceSecret = "ga7XA6KdlEeiPXQPpRbAjOZXwG8y****";

// 计算MQTT连接参数。

MqttSign sign = new MqttSign();

sign.calculate(productKey, deviceName, deviceSecret);

Console.WriteLine("username: " + sign.getUsername());

Console.WriteLine("password: " + sign.getPassword());

Console.WriteLine("clientid: " + sign.getClientid());

调用Paho MQTT客户端连接物联网平台。 // 使用Paho连接阿里云物联网平台。

int port = 443;

String broker = productKey + ".iot-as-mqtt.cn-shanghai.aliyuncs.com";

MqttClient mqttClient = new MqttClient(broker, port, true, MqttSslProtocols.TLSv1_2, null, null);

mqttClient.Connect(sign.getClientid(), sign.getUsername(), sign.getPassword());

Console.WriteLine("Broker: " + broker + " Connected");

说明

代码中的地域代码(cn-shanghai)，需设置为您的物联网平台设备所在地域代码。地域代码表达方法，请参见

设备上报数据到物联网平台。

以下示例代码上报物模型属性LightSwitch。// Paho MQTT消息发布。

String topic = "/sys/" + productKey + "/" + deviceName + "/thing/event/property/post";

String message = "{\"id\":\"1\",\"version\":\"1.0\",\"params\":{\"LightSwitch\":0}}";

mqttClient.Publish(topic, Encoding.UTF8.GetBytes(message));

物模型通信数据格式，请参见

如果您要使用自定义Topic通信，请参见

订阅Topic，接收物联网平台下发数据。

以下示例中，订阅的是上报属性值后，物联网平台返回应答消息的Topic。// Paho MQTT消息订阅。

String topicReply = "/sys/" + productKey + "/" + deviceName + "/thing/event/property/post_reply";

mqttClient.MqttMsgPublishReceived += MqttPostProperty_MqttMsgPublishReceived;

mqttClient.Subscribe(new string[] { topicReply }, new byte[] { MqttMsgBase.QOS_LEVEL_AT_MOST_ONCE });

...

private static void MqttPostProperty_MqttMsgPublishReceived(object sender, uPLibrary.Networking.M2Mqtt.Messages.MqttMsgPublishEventArgs e)

{

Console.WriteLine("reply topic :" + e.Topic);

Console.WriteLine("reply payload:" + e.Message.ToString());

}