M2mqtt 使用字符串變量訂閱主題

Question

client.Subscribe(new string[] { "hello/world" }, new byte[] {MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE });

我正在測試上述內容，它工作得很好。 但是...當我嘗試以下操作時，我的代碼根本不起作用，也不會引發任何異常。

string variable = "hello/world";
client.Subscribe(new string[] { variable }, new byte[] { MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE });

我已經嘗試過：

string variable = "hello/world";
string[] stringArray = new string[] { variable };
client.Subscribe(stringArray, new byte[] { MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE });

還：

 string variable = "hello/world";
 client.Subscribe(new []{ variable }, new byte[] { MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE });

我怎樣才能讓它正常工作？

謝謝！

@edit：服務器端日志：

Server auth 2b6240f1-593a-4217-b3d5-ae8c666099ca from 127.0.0.1    
Client 2b6240f1-593a-4217-b3d5-ae8c666099ca connected
Total connections: 3
$SYS/LIZO1uD/new/clients 2b6240f1-593a-4217-b3d5-ae8c666099ca

當客戶端連接並訂閱時：

Server auth 6ba2d202-f595-4e37-a1d4-8ae6b134a370 from 127.0.0.1
Client 6ba2d202-f595-4e37-a1d4-8ae6b134a370 connected
Total connections: 3
$SYS/LIZO1uD/new/clients 6ba2d202-f595-4e37-a1d4-8ae6b134a370
$SYS/LIZO1uD/new/subscribes {"clientId":"6ba2d202-f595-4e37-a1d4-8ae6b134a370","topic":"hello/world"}

Answer 1

我已經整理了一個快速工作的例子。 試試看你是否得到任何結果。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using uPLibrary.Networking.M2Mqtt;
using uPLibrary.Networking.M2Mqtt.Messages;

namespace MqttApp
{
    class Program
    {
        static void Main(string[] args)
        {
            string BrokerAdress = "mqtt.server.local";
            string ClientID = "CSharpMqttClient";
            string Topic = "hello/world";
            string MessageToPublish;
            //Create MQTT client instance

            MqttClient mqttClient = new MqttClient(BrokerAdress);
            Console.WriteLine("mqttClient instaceed for broker " + BrokerAdress);

            // register to message received 
            mqttClient.MqttMsgPublishReceived += client_MqttMsgPublishReceived;

            //Subscribe to the indicated topic
            // subscribe to the topic with QoS 2 

            mqttClient.Subscribe(new string[] {Topic}, new byte[] { MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE });

            //Connect mqttCient

            mqttClient.Connect(ClientID,"","",true,60);

            Console.WriteLine(ClientID + " connected");
            // publish messages on "hello world" topic with QoS 2 

            MessageToPublish = "hello world";
            mqttClient.Publish(Topic, Encoding.UTF8.GetBytes(MessageToPublish), MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE, false);
            System.Console.WriteLine("Published message: " + MessageToPublish);

          }

        static void client_MqttMsgPublishReceived(object sender, MqttMsgPublishEventArgs e)
        {
            // handle message received 
            var msg = System.Text.Encoding.Default.GetString(e.Message);
            System.Console.WriteLine("Message Received: " + msg);
        }

    }
}