MQTTnet 2.8 的使用

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netcore3.1控制檯應用程序，引入MQTTnet 2.8版本

訂閱端：

using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using System;
using System.Text;
using MQTTnet;
using MQTTnet.Server; 
using MQTTnet.Client;
using System.Threading;
using System.Threading.Tasks;
using System.Collections.Generic;
using MQTTnet.Protocol;

namespace swapConsole
{
    class Program
    {
        private static MqttClient mqttClient = null;
        private static  string topic = "test123ABC";
        private static IMqttClientOptions Options
        {
            get
            {
                MqttClientOptionsBuilder builder = new MqttClientOptionsBuilder(); 
                builder.WithCleanSession(false);
                //用戶名 密碼
                builder.WithCredentials("", "");
                var id = Guid.NewGuid().ToString();
                builder.WithClientId(id);
                builder.WithTcpServer("1270.0.0.0", 1883);
                return builder.Build();
            }
        }
        static async Task Main(string[] args)
        {
            MqttFactory factory = new MqttFactory();
            if (mqttClient == null)
            {
                mqttClient = (MqttClient)factory.CreateMqttClient();
                mqttClient.ApplicationMessageReceived += MqttClient_ApplicationMessageReceived;
                mqttClient.Connected += MqttClient_Connected;
                mqttClient.Disconnected += async (s, e) =>
                 {
                     Console.WriteLine("嘗試重連！" + Environment.NewLine);
                     await ConnectToServer();
                 };
            }
            await ConnectToServer(); 

            Console.ReadLine();
        }
        /// <summary>
        /// 連接MQTT服務器
        /// </summary>
        private   static async Task ConnectToServer()
        {
            try
            {
                var res =await  mqttClient.ConnectAsync(Options);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"連接到MQTT服務器失敗！" + Environment.NewLine + ex.Message + Environment.NewLine);
            }
        }
        /// <summary>
        /// 連接MQTT服務器觸發
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private static void MqttClient_Connected(object sender, EventArgs e)
        {
            Console.WriteLine("已連接到MQTT服務器！" + Environment.NewLine);
            SubscribeInfo();
        }

        /// <summary>
        /// 接收消息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private static void MqttClient_ApplicationMessageReceived(object sender, MqttApplicationMessageReceivedEventArgs e)
        {
            Console.WriteLine($">> {Encoding.UTF8.GetString(e.ApplicationMessage.Payload)}{Environment.NewLine}");
        }

        /// <summary>
        /// 訂閱消息
        /// </summary>
        public static void SubscribeInfo()
        {
            if (string.IsNullOrEmpty(topic))
            {
                Console.WriteLine("訂閱主題不能爲空！");
                return;
            }

            if (!mqttClient.IsConnected)
            {
                Console.WriteLine("MQTT客戶端尚未連接！");

                return;
            }
            mqttClient.SubscribeAsync(new List<TopicFilter> {
                new  TopicFilter(topic, MqttQualityOfServiceLevel.ExactlyOnce)
            });

            Console.WriteLine($"已訂閱[{topic}]主題" + Environment.NewLine);
        }

        /// <summary>
        /// 退訂消息
        /// </summary>
        public static void UnSubscribeInfo()
        { 

            if (string.IsNullOrEmpty(topic))
            {
                Console.WriteLine("退訂主題不能爲空！");
                return;
            }
            if (!mqttClient.IsConnected)
            {
                Console.WriteLine("MQTT客戶端尚未連接！");
                return;
            }
            mqttClient.UnsubscribeAsync(topic);
            Console.WriteLine($"已退訂[{topic}]主題" + Environment.NewLine);
        }

    }
}

發佈端：

using MQTTnet;
using MQTTnet.Client;
using System;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace swapPublish
{
    class Program
    {
        private static MqttClient mqttClient = null;
        private static string topic = "test123ABC";
        private static IMqttClientOptions Options
        {
            get
            {
                MqttClientOptionsBuilder builder = new MqttClientOptionsBuilder();
                builder.WithCleanSession(false);
                //用戶名 密碼
                builder.WithCredentials("", "");
                var id = Guid.NewGuid().ToString();
                builder.WithClientId(id);
                builder.WithTcpServer("127.0.0.1", 1883);
                return builder.Build();
            }
        }
        static async Task  Main(string[] args)
        {
            MqttFactory factory = new MqttFactory();
            if (mqttClient == null)
            {
                mqttClient = (MqttClient)factory.CreateMqttClient(); 
                mqttClient.Connected += MqttClient_Connected;
                mqttClient.Disconnected += async(s, e) =>
                {
                    Console.WriteLine("嘗試重連！" + Environment.NewLine);
                    await ConnectToServer();
                };
            }
           await  ConnectToServer();
            Console.WriteLine("已斷開MQTT連接！" + Environment.NewLine);

            Console.ReadLine();
        }
        /// <summary>
        /// 連接MQTT服務器
        /// </summary>
        private static async Task ConnectToServer()
        {
            try
            {
                var res = await mqttClient.ConnectAsync(Options);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"連接到MQTT服務器失敗！" + Environment.NewLine + ex.Message + Environment.NewLine);
            }
        }
        /// <summary>
        /// 連接MQTT服務器觸發
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private static void MqttClient_Connected(object sender, EventArgs e)
        {
            Console.WriteLine("已連接到MQTT服務器！" + Environment.NewLine);
            for(int i = 0; i < 10; i++)
            {
                var tak = PublishInfo(); 
                Thread.Sleep(2000);
            }
          
        }

        private static async  Task PublishInfo( )
        { 

            if (string.IsNullOrEmpty(topic))
            {
               Console.WriteLine("發佈主題不能爲空！");
                return;
            }

            string inputString = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
            MqttApplicationMessageBuilder builder = new MqttApplicationMessageBuilder(); 
            builder.WithPayload(Encoding.UTF8.GetBytes(inputString));
            builder.WithTopic(topic);
            builder.WithRetainFlag(false);
            builder.WithExactlyOnceQoS();
            await mqttClient.PublishAsync(builder.Build());
        }
    }
}

如何使用通配符，如何只允許一個客戶端消費同一個消息，暫時未解決！

大家有解決方法，請貼出評論。謝謝