C#MQTT协议服务器与客户端通讯实现
- [1 DLL版本](#1 DLL版本)
- [2 服务器](#2 服务器)
- [3 客户端](#3 客户端)
1 DLL版本
MQTTnet.DLL版本-2.7.5.0
基于比较老的项目中应用的DLL，其他更高版本变化可能较大，谨慎参考。
2 服务器
开启服务器
关闭服务器
绑定事件【客户端连接服务器事件】
绑定事件【客户端断开(服务器)连接事件】
绑定事件【客户端订阅主题事件】
绑定事件【客户端退订主题事件】
绑定事件【接收客户端(发送)消息事件】
csharp
using System;
using System.Net;
using MQTTnet;
using MQTTnet.Server;
namespace Demo_MQTT.Model
{
public class ServerModel
{
private static MqttServer _mqttServer = null;
private readonly Action<string> _callbackLog;
public ServerModel(Action<string> callbackLog)
{
_callbackLog = callbackLog;
}
/// <summary>
/// 绑定客户端连接服务器事件
/// </summary>
private void MqttServer_ClientConnected(object sender, MqttClientConnectedEventArgs e)
{
WriteLog($"客户端[{e.Client.ClientId}]已连接 {DateTime.Now:yyyy-MM-dd HH:mm:ss}{Environment.NewLine}");
}
/// <summary>
/// 绑定客户端断开连接事件
/// </summary>
private void MqttServer_ClientDisconnected(object sender, MqttClientDisconnectedEventArgs e)
{
WriteLog($"客户端[{e.Client.ClientId}]已断开连接 {DateTime.Now:yyyy-MM-dd HH:mm:ss}{Environment.NewLine}");
}
/// <summary>
/// 绑定客户端订阅主题事件
/// </summary>
private void Server_ClientSubscribedTopic(object sensor, MqttClientSubscribedTopicEventArgs e)
{
WriteLog($">>> 客户端{e.ClientId}订阅主题{e.TopicFilter.Topic}");
}
/// <summary>
/// 绑定客户端退订主题事件
/// </summary>
/// <param name="e"></param>
private void Server_ClientUnsubscribedTopic(object sensor, MqttClientUnsubscribedTopicEventArgs e)
{
WriteLog($">>> 客户端{e.ClientId}退订主题{e.TopicFilter}");
}
/// <summary>
/// 绑定接收客户端消息事件
/// </summary>
private void MqttServer_ApplicationMessageReceived(object sender, MqttApplicationMessageReceivedEventArgs e)
{
WriteLog($"接收到{e.ClientId}发送来的消息！ {DateTime.Now:yyyy-MM-dd HH:mm:ss} {Environment.NewLine}");
}
private void WriteLog(string log)
{
_callbackLog?.Invoke(log);
}
/// <summary>
/// 开启服务器
/// </summary>
/// <param name="ip">IP地址</param>
/// <param name="port">端口号</param>
public void StartServer(string ip, int port)
{
if (_mqttServer == null)
{
var optionsBuilder = new MqttServerOptionsBuilder()
.WithDefaultEndpointBoundIPAddress(IPAddress.Parse(ip))
.WithConnectionBacklog(1000)
.WithDefaultEndpointPort(port);
IMqttServerOptions options = optionsBuilder.Build();
try
{
_mqttServer = new MqttFactory().CreateMqttServer() as MqttServer;
_mqttServer.ClientConnected += MqttServer_ClientConnected;
_mqttServer.ClientDisconnected += MqttServer_ClientDisconnected;
_mqttServer.ApplicationMessageReceived += MqttServer_ApplicationMessageReceived;
_mqttServer.ClientSubscribedTopic += Server_ClientSubscribedTopic;
_mqttServer.ClientUnsubscribedTopic += Server_ClientUnsubscribedTopic;
_mqttServer.StartAsync(options);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
return;
}
WriteLog($"MQTT服务器启动成功 {DateTime.Now:yyyy-MM-dd HH:mm:ss}{Environment.NewLine}");
}
}
/// <summary>
/// 关闭服务器
/// </summary>
public void CloseServer()
{
_mqttServer?.StopAsync();
}
}
}3 客户端
连接服务器
属性：客户端连接状态
客户端断开重连线程
获取所有订阅主题
订阅主题
退订主题
发送消息
绑定事件【客户端连接服务器事件】
绑定事件【客户端断开(服务器)连接事件】
绑定事件【客户端接收消息事件】
csharp
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using MQTTnet;
using MQTTnet.Client;
using MQTTnet.Protocol;
namespace Demo_MQTT.Model
{
public class ClientModel
{
/// <summary>
/// 记录所有订阅主题，用于断开重连时重新订阅主题
/// </summary>
private readonly List<string> _subscribeTopics = new List<string>();
private MqttClient _mqttClient = null;
private string _serverIp;
private int _nServerPort;
private bool _isRunningReConnectThreadStart = false;
private string _clienID;
/// <summary>
/// 接受消息回调函数，参数：主题，消息内容
/// </summary>
private readonly Action<string, byte[]> _callbackReceived;
private readonly Action<string> _callbackLog;
/// <summary>
/// 构造函数
/// </summary>
/// <param name="callbackReceived">接受消息回调函数，参数：主题，消息内容</param>
/// <param name="callbackLog"></param>
public ClientModel(Action<string, byte[]> callbackReceived, Action<string> callbackLog)
{
_callbackReceived = callbackReceived;
_callbackLog = callbackLog;
}
/// <summary>
/// 连接服务器
/// </summary>
private async void ConnectServer()
{
try
{
if (_mqttClient == null)
{
_mqttClient = new MqttFactory().CreateMqttClient() as MqttClient;
_mqttClient.Connected += (s, a) => WriteLog($"【{_clienID}】已连接到MQTT服务器!");
_mqttClient.Disconnected += (s, a) => WriteLog($"【{_clienID}】已断开MQTT连接!");
_mqttClient.ApplicationMessageReceived += (sender, args) =>
{
_callbackReceived?.Invoke(args.ApplicationMessage.Topic, args.ApplicationMessage.Payload);
};
}
if (_mqttClient.IsConnected) return;
IMqttClientOptions options = new MqttClientOptions
{
ChannelOptions = new MqttClientTcpOptions()
{
Server = _serverIp,
Port = _nServerPort
},
CleanSession = true
};
_clienID = options.ClientId;
await _mqttClient.ConnectAsync(options);
if (_mqttClient.IsConnected)
{
ReConnectThreadStart();
SubscribeAsync();
}
}
catch (Exception ex)
{
WriteLog("连接到MQTT服务器失败!");
}
}
/// <summary>
/// 客户端重连服务器线程-启动
/// </summary>
/// <returns></returns>
private void ReConnectThreadStart()
{
if (_isRunningReConnectThreadStart) return;
if (_mqttClient != null)
{
new Task(() =>
{
_isRunningReConnectThreadStart = true;
Thread.Sleep(5000);
while (true)
{
Thread.Sleep(1000);
if (!IsConnect)
{
WriteLog($"客户端[{_clienID}]断开连接，尝试重新连接服务器中...");
int i;
for (i = 0; i < 60; i++)
{
if (IsConnect) break;
WriteLog($"尝试第{i + 1}次连接服务器");
ConnectServer();
Thread.Sleep(1000);
if (IsConnect) break;
}
_isRunningReConnectThreadStart = i < 60;
}
if (!_isRunningReConnectThreadStart) break;
}
}).Start();
}
}
private void WriteLog(string log)
{
_callbackLog?.Invoke(log);
}
/// <summary>
/// 客户端连接状态
/// </summary>
public bool IsConnect => _mqttClient?.IsConnected == true;
/// <summary>
/// 连接服务器
/// </summary>
/// <param name="serverIp">服务器IP</param>
/// <param name="serverPort">服务器端口</param>
/// <param name="topic"></param>
public async void ConnectServer(string serverIp, int serverPort)
{
_serverIp = serverIp;
_nServerPort = serverPort;
await Task.Run(() => { ConnectServer(); });
}
/// <summary>
/// 关闭客户端，断开客户端和服务器的连接
/// </summary>
public void CloseClient()
{
_mqttClient.DisconnectAsync();
}
/// <summary>
/// 发送消息
/// </summary>
/// <param name="topic">发送主题</param>
/// <param name="cmd">发送内容</param>
[Obsolete("Obsolete")]
public void PublishAsync(string topic, string cmd)
{
var bytes = Encoding.UTF8.GetBytes(cmd);
var mode = MqttQualityOfServiceLevel.AtMostOnce;
var appMsg = new MqttApplicationMessage(topic, bytes, mode, false);
_mqttClient.PublishAsync(appMsg);//发送消息
}
/// <summary>
/// 订阅主题
/// </summary>
/// <param name="topics">主题标识</param>
public void SubscribeAsync(params string[] topics)
{
foreach (var topic in topics)
{
if (!_subscribeTopics.Contains(topic))
{
_subscribeTopics.Add(topic);
}
}
var topicFilters = _subscribeTopics.Select(topic => new TopicFilter(topic, MqttQualityOfServiceLevel.AtMostOnce)).ToList();
_mqttClient?.SubscribeAsync(topicFilters);
}
/// <summary>
/// 退订已订阅主题
/// </summary>
/// <param name="topics">主题标识</param>
public void UnSubscribeAsync(params string[] topics)
{
if (topics == null || topics.Length == 0) return;
var topicFilters = topics.Select(topic => new TopicFilter(topic, MqttQualityOfServiceLevel.AtMostOnce)).ToList();
_mqttClient.SubscribeAsync(topicFilters);
}
/// <summary>
/// 获取所有订阅主题
/// </summary>
public string[] GetAllTopic => _subscribeTopics.ToArray();
}
}