使用M2Mqtt 接受以及发布MQTT消息

在NuGet库里面直接查找M2Mqtt就可以安装库。
使用framework4.5.2
1.配置文件操作

  public static class GModel
    {
        public static BassSetup  MainSetup { get; set; }
        public static void GetThisAdd()
        {
            MainSetup = new BassSetup();
            string IPAdd = ConfigurationManager.AppSettings["IPAdd"];
            string ServerPort = ConfigurationManager.AppSettings["ServerPort"];
            string UserName = ConfigurationManager.AppSettings["UserName"];
            string Pwd = ConfigurationManager.AppSettings["Pwd"];
            MainSetup.IPAdd = IPAdd ;
            MainSetup.ServerPort =int.Parse(ServerPort);
            MainSetup.UserName = UserName;
            MainSetup.Pwd = Pwd;

           
        }
    }

2连接服务器：

        /// 

        /// 连接服务
        /// 
        /// 
        /// 

        private void button4_Click(object sender, EventArgs e)
        {
            string EMQX_CLIENT_ID = Guid.NewGuid().ToString();
            mqttClient = new MqttClient(GModel.MainSetup.IPAdd, GModel.MainSetup.ServerPort, false, null, null, MqttSslProtocols.None); 
            //mqttClient = new MqttClient("http://192.168.0.197:61613");此方法不妥
            mqttClient.Connect(EMQX_CLIENT_ID,GModel.MainSetup.UserName,GModel.MainSetup.Pwd);//需要录入账号密码
            mqttClient.MqttMsgPublishReceived += Client_MqttMsgPublishReceived;//订阅后的动作
            //mqttClient.Subscribe(new string[] { "123123124124512" }, new byte[] { MqttMsgBase.QOS_LEVEL_AT_MOST_ONCE });
            BTConnect.BackColor = Color.Green;
        }

3.订阅后的事件

 //这段定义了收到消息之后做什么事情
        private void Client_MqttMsgPublishReceived(object sender, MqttMsgPublishEventArgs e)
        {
            string topic = e.Topic.ToString();
            string message = System.Text.Encoding.Default.GetString(e.Message);
            //同时订阅两个或者以上主题时，分类收集收到的信息
           
            //reciveTopic.Text = topic;
            //reciveMessagetxt.Text = message;

        }

4.订阅主题

       /// 

        /// 订阅
        /// 
        /// 
        /// 
        private void button1_Click(object sender, EventArgs e)
        {
            if (mqttClient != null && !string.IsNullOrEmpty(TBZhuti.Text)  )
            {
                mqttClient.Subscribe(new string[] { TBZhuti.Text}, new byte[] { MqttMsgBase.QOS_LEVEL_AT_MOST_ONCE });//一次订阅多个主题似乎会出错
            }
            else
            {
                MessageBox.Show("请先连接服务器，并且确认订阅主题有数据。",this.Text,MessageBoxButtons.OK,MessageBoxIcon.Information);
            }
            
        }

5.发布主题。

        /// 

        /// 发布
        /// 
        /// 
        /// 
        private void button2_Click(object sender, EventArgs e)
        {
            if (mqttClient != null && !string.IsNullOrEmpty(TBZhuti.Text) && !string.IsNullOrEmpty(RTBContent.Text))
            {
                mqttClient.Publish(TBZhuti.Text, System.Text.Encoding.UTF8.GetBytes(RTBContent.Text), MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE, false);
            }
        }

6，解除订阅

 /// 

         /// 解除订阅
         /// 
         /// 
         /// 

        private void button3_Click(object sender, EventArgs e)
        {
            mqttClient.Unsubscribe(new string[] { "AAAAAA242" });
        }

7.断开服务器连接

 /// 

        ///  断开连接
        /// 
        /// 
        /// 
        private void DisConnect_Click(object sender, EventArgs e)
        {
            mqttClient.Disconnect();
        }

https://github.com/eclipse/paho.mqtt.m2mqtt