We_Message/MqttMsgServer/Tools/MqttHelper.cs

using MQTTnet;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MQTTnet.Protocol;
using MQTTnet.Server;

namespace MqttMsgServer.Tools
{
    public class MqttHelper
    {
        public static IMqttServer Server { get; set; }

        public static void PublishAsync(string topic, byte[] payLoad)
        {
            Server?.PublishAsync(new MqttApplicationMessage()
            {
                Topic = topic,
                Payload = payLoad
            }, new System.Threading.CancellationToken(false));
        }
        public static void PublishAsync(string topic, string payload)
        {
            Server?.PublishAsync(new MQTTnet.MqttApplicationMessage()
            {

                Topic = topic,
                Payload = Encoding.UTF8.GetBytes(payload)
            }, new System.Threading.CancellationToken(false));
        }

        public static async Task<bool> CheckExistClient(string clientId)
        {
            var list = await Server.GetClientStatusAsync();
            var client = list.FirstOrDefault(i => i.ClientId == clientId);
            //if (client != null)
            //{
            //    await client.DisconnectAsync();
            //}
            return client != null;
        }
        public static async Task SubscribeAsync(string clientId, string topic)
        {
            var topicFilter = new MqttTopicFilter()
            { Topic = topic, QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce, NoLocal = true };
            await SubscribeAsync(clientId, topicFilter);
        }
        public static async Task SubscribeAsync(string clientId, MqttTopicFilter topicFilter)
        {
            List<MqttTopicFilter> topicFilters = new List<MqttTopicFilter>() { topicFilter };
            await SubscribeAsync(clientId, topicFilters);
        }
        public static async Task SubscribeAsync(string clientId, List<MqttTopicFilter> topicFilters)
        {
            if (await CheckExistClient(clientId))
            {
                Server?.SubscribeAsync(clientId, topicFilters);
            }
        }

        public static async Task UnsubscribeAsync(string clientId, List<string> topicFilters)
        {
            if (await CheckExistClient(clientId))
            {
                Server?.UnsubscribeAsync(clientId, topicFilters);
            }
        }
        public static async Task UnSubscribeAsync(string clientId, string topic)
        {

            await UnsubscribeAsync(clientId, new List<string>() { topic });
        }


       





    }
}