MQTT Client ASP.NET Core

This repository is an example of how to use MQTTnet client in ASP.NET core web application with services.

MQTT Client is running in MqttClientService byIHostedService, and it is a singleton service.

To access MqttClientService from other external services inject MQTTClientServiceProvider in service constructor.

Here is an example

public class ExtarnalService
{
    private readonly IMqttClientService mqttClientService;
    public ExtarnalService(MqttClientServiceProvider provider)
    {
        mqttClientService = provider.MqttClientService;
    }
}

Configuration

Configure your MQTT settings in appSettings.json

"BrokerHostSettings": {
    "Host": "localhost",
    "Port": 1883
  },

  "ClientSettings": {
    "Id": "5eb020f043ba8930506acbdd",
    "UserName": "rafiul",
    "Password": "12345678"
  },

Reconnecting

Reference Code：https://github.com/dotnet/MQTTnet/blob/master/Samples/Client/Client_Connection_Samples.cs The implemented code is in MqttClientService.cs

1. Reconnect_Using_Event

   public async Task HandleDisconnectedAsync(MqttClientDisconnectedEventArgs eventArgs)
   {
   
         if (e.ClientWasConnected)
         {
              // Use the current options as the new options.
              await mqttClient.ConnectAsync(mqttClient.Options);
         }
   }

   "Reconnect_Using_Event" is not recommended, so the code is commented out ,the following code is recommended "Reconnect_Using_Time"

2. Reconnect_Using_Timer

   public async Task StartAsync(CancellationToken cancellationToken)
   {
          await mqttClient.ConnectAsync(options);
          /* 
           * This sample shows how to reconnect when the connection was dropped.
           * This approach uses a custom Task/Thread which will monitor the connection status.
           * This is the recommended way but requires more custom code!
           */
           _ = Task.Run(
              async () =>
              {
                  // // User proper cancellation and no while(true).
                  while (true)
                  {
                      try
                      {
                          // This code will also do the very first connect! So no call to _ConnectAsync_ is required in the first place.
                          if (!await mqttClient.TryPingAsync())
                          {
                              await mqttClient.ConnectAsync(mqttClient.Options, CancellationToken.None);
   
                              // Subscribe to topics when session is clean etc.
                              _logger.LogInformation("The MQTT client is connected.");
                          }
                      }
                      catch (Exception ex)
                      {
                          // Handle the exception properly (logging etc.).
                          _logger.LogError(ex, "The MQTT client  connection failed");
                      }
                      finally
                      {
                          // Check the connection state every 5 seconds and perform a reconnect if required.
                          await Task.Delay(TimeSpan.FromSeconds(5));
                      }
                  }
              });
   
    }

Now do whatever you want to do with MQTTClientService!