类本体
4.3.0

public   class MQTTMain{public   MqttClient mqttClient =null ; public   bool MQTTMainConnect(string MenZuNo, string ServerIP, int ServerPort, string UserName, string Pwd){try{string EMQX_CLIENT_ID = $"称重端-{MenZuNo}-{OPCommon.PCControl.GetPCInfos.GetMachineName()}";mqttClient = new MqttClient(ServerIP, ServerPort, false, null, null, MqttSslProtocols.None);mqttClient.Connect(EMQX_CLIENT_ID, UserName, Pwd);//需要录入账号密码return true; }catch (Exception ex){OPCommon.LogWrite.WriteLog("MQTT链接错误，信息是:"+ex.Message);return false;} }/// <summary>/// 发布主题/// </summary>/// <param name="MenZuNo"></param>/// <param name="ServerIP"></param>/// <param name="ServerPort"></param>/// <param name="UserName"></param>/// <param name="Pwd"></param>/// <returns></returns>public   bool MQTTMainPublish(string Zhuti, string MsgInfo ){try{mqttClient.Publish(Zhuti, System.Text.Encoding.UTF8.GetBytes(MsgInfo), MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE, false);return true;}catch (Exception ex){OPCommon.LogWrite.WriteLog("MQTT发送错误，信息是:" + ex.Message);return false;}}

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连接的应用

 /// <summary>/// MQTT链接重新连接/// </summary>public void ThisMQTTConntect(){if (ThisMQTTS.mqttClient == null || !ThisMQTTS.mqttClient.IsConnected){ThisMQTTS.MQTTMainConnect(GModel.MainSetupAll.BangNo, GModel.MainSetupAll.ServerIp, GModel.MainSetupAll.ServerPort, GModel.MainSetupAll.ServerUser, GModel.MainSetupAll.Pwd);}if (ThisMQTTS.mqttClient != null && ThisMQTTS.mqttClient.IsConnected){ThisMQTTS.mqttClient.MqttMsgPublishReceived += Client_MqttMsgPublishReceived;ThisMQTTS.mqttClient.ConnectionClosed += TryReconnectAsync;ThisMQTTS.mqttClient.Subscribe(new string[] { GModel.DingyueZhuti }, new byte[] { MqttMsgBase.QOS_LEVEL_AT_MOST_ONCE });//订阅主题}}

断开重连：

 private void TryReconnectAsync(object sender, EventArgs ex){if (!ThisMQTTS.mqttClient.IsConnected && !IsThisClose){OPCommon.LogWrite.WriteLog($"{this.Name}当前断开");Thread.Sleep(2000);Thread retryThread = new Thread(new ThreadStart(delegate{OPCommon.LogWrite.WriteLog($"{this.Name}第一次重连");ThisMQTTConntect();if (!ThisMQTTS.mqttClient.IsConnected){OPCommon.LogWrite.WriteLog($"{this.Name}第二次重连！");Thread.Sleep(5000);ThisMQTTConntect();}else{OPCommon.LogWrite.WriteLog($"{this.Name}第一次重连成功！");}}));retryThread.Start();} } 

MQTT数据接受

/// <summary>///  MQTT操作/// </summary>/// <param name="sender"></param>/// <param name="e"></param>private void Client_MqttMsgPublishReceived(object sender, MqttMsgPublishEventArgs e){//string topic = e.Topic.ToString();//主题内容string MsgFromMQTT = System.Text.Encoding.UTF8.GetString(e.Message);//数据内容}

发送数据

 if (ThisMQTTS.mqttClient != null && ThisMQTTS.mqttClient.IsConnected){ThisMQTTS.MQTTMainPublish(GModel.DingyueZhuti, SetToServer);OPCommon.LogWrite.WriteLog("数据发送成功：" + SetToServer);ChengzhongMainWath.Restart();}