C#MQTT编程06--MQTT服务器和客户端(winform版)

时间：2024-04-27 14:10:12 来源：网络cs 作者：欧阳逸栏目：选词工具阅读：

标签：服务

1、前言

介绍完基础理论部分，下面在Windows平台上搭建一个简单的MQTT应用，进行简单的应用，整体架构如下图所示；

消息模型：

运用MQTT协议，设备可以很方便地连接到物联网云服务，管理设备并处理数据，最后应用到各种业务场景，如下图所示

前面介绍过，MQTT可以运行在几乎所有的平台，windows,linux什么的都可以，各种语言都有实现MQTT的组件，.net也好，Java也好，都有封装好的mqtt服务器和客户端组件或插件来实现，本系列是在.net平台下实现mqtt的服务器和客户端。

常见的MQTT服务器包括Eclipse Mosquitto、EMQ X、HiveMQ、RabbitMQ、MQTTNET等，本系列文章都是基于.net平台的mqtt服务通信，开发环境vs2022，.net framework4.8。

2、服务器搭建

1、创建项目方案

2、添加库引用

3、UI布局

4、控件代码

“启动”按钮

停止按钮

窗体加载

全部完整代码

注意这里面用到了多线程及任务task，委托action，异步async及await的技术，在mqtt中必须使用这些技术，否则界面会卡死。

using MQTTnet.Client.Receiving;using MQTTnet.Server;using MQTTnet;using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;using MQTTnet.Protocol;namespace MQTTNETServerForms{    public partial class Form1 : Form    {        private IMqttServer server;//mqtt服务器对象        List<TopicItem> Topics = new List<TopicItem>();        public Form1()        {            InitializeComponent();        }        private void Form1_Load(object sender, EventArgs e)        {            //创建服务器对象            server = new MqttFactory().CreateMqttServer();            server.ApplicationMessageReceivedHandler = new MqttApplicationMessageReceivedHandlerDelegate(new Action<MqttApplicationMessageReceivedEventArgs>(Server_ApplicationMessageReceived));//绑定消息接收事件            server.ClientConnectedHandler = new MqttServerClientConnectedHandlerDelegate(new Action<MqttServerClientConnectedEventArgs>(Server_ClientConnected));//绑定客户端连接事件            server.ClientDisconnectedHandler = new MqttServerClientDisconnectedHandlerDelegate(new Action<MqttServerClientDisconnectedEventArgs>(Server_ClientDisconnected));//绑定客户端断开事件            server.ClientSubscribedTopicHandler = new MqttServerClientSubscribedHandlerDelegate(new Action<MqttServerClientSubscribedTopicEventArgs>(Server_ClientSubscribedTopic));//绑定客户端订阅主题事件            server.ClientUnsubscribedTopicHandler = new MqttServerClientUnsubscribedTopicHandlerDelegate(new Action<MqttServerClientUnsubscribedTopicEventArgs>(Server_ClientUnsubscribedTopic));//绑定客户端退订主题事件            server.StartedHandler = new MqttServerStartedHandlerDelegate(new Action<EventArgs>(Server_Started));//绑定服务端启动事件            server.StoppedHandler = new MqttServerStoppedHandlerDelegate(new Action<EventArgs>(Server_Stopped));//绑定服务端停止事件        }        /// <summary>        /// 绑定消息接收事件        /// </summary>        /// <param name="e"></param>        private void Server_ApplicationMessageReceived(MqttApplicationMessageReceivedEventArgs e)        {            string msg = e.ApplicationMessage.ConvertPayloadToString();            WriteLog(">>> 收到消息：" + msg + "，QoS =" + e.ApplicationMessage.QualityOfServiceLevel + "，客户端=" + e.ClientId + "，主题：" + e.ApplicationMessage.Topic);        }        /// <summary>        /// 绑定客户端连接事件        /// </summary>        /// <param name="e"></param>        private void Server_ClientConnected(MqttServerClientConnectedEventArgs e)        {            Task.Run(new Action(() =>            {                lbClients.BeginInvoke(new Action(() =>                {                    lbClients.Items.Add(e.ClientId);                }));            }));            WriteLog(">>> 客户端" + e.ClientId + "连接");        }        /// <summary>        /// 绑定客户端断开事件        /// </summary>        /// <param name="e"></param>        private void Server_ClientDisconnected(MqttServerClientDisconnectedEventArgs e)        {            Task.Run(new Action(() =>            {                lbClients.BeginInvoke(new Action(() =>                {                    lbClients.Items.Remove(e.ClientId);                }));            }));            WriteLog(">>> 客户端" + e.ClientId + "断开");        }        /// <summary>        /// 绑定客户端订阅主题事件        /// </summary>        /// <param name="e"></param>        private void Server_ClientSubscribedTopic(MqttServerClientSubscribedTopicEventArgs e)        {            Task.Run(new Action(() =>            {                var topic = Topics.FirstOrDefault(t => t.Topic == e.TopicFilter.Topic);                if (topic == null)                {                    topic = new TopicItem { Topic = e.TopicFilter.Topic, Count = 0 };                    Topics.Add(topic);                }                if (!topic.Clients.Exists(c => c == e.ClientId))                {                    topic.Clients.Add(e.ClientId);                    topic.Count++;                }                lvTopic.Invoke(new Action(() =>                {                    this.lvTopic.Items.Clear();                }));                foreach (var item in this.Topics)                {                    lvTopic.Invoke(new Action(() =>                    {                        this.lvTopic.Items.Add($"{item.Topic}:{item.Count}");                    }));                }            }));            WriteLog(">>> 客户端" + e.ClientId + "订阅主题" + e.TopicFilter.Topic);        }        /// <summary>        /// 绑定客户端退订主题事件        /// </summary>        /// <param name="e"></param>        private void Server_ClientUnsubscribedTopic(MqttServerClientUnsubscribedTopicEventArgs e)        {            Task.Run(new Action(() =>            {                var topic = Topics.FirstOrDefault(t => t.Topic == e.TopicFilter);                if (topic != null)                {                    topic.Count--;                    topic.Clients.Remove(e.ClientId);                }                this.lvTopic.Items.Clear();                foreach (var item in this.Topics)                {                    this.lvTopic.Items.Add($"{item.Topic}:{item.Count}");                }            }));            WriteLog(">>> 客户端" + e.ClientId + "退订主题" + e.TopicFilter);        }        /// <summary>        /// 绑定服务端启动事件        /// </summary>        /// <param name="e"></param>        private void Server_Started(EventArgs e)        {            WriteLog(">>> 服务端已启动！");        }        /// <summary>        /// 绑定服务端停止事件        /// </summary>        /// <param name="e"></param>        private void Server_Stopped(EventArgs e)        {            WriteLog(">>> 服务端已停止！");        }        /// <summary>        /// 显示日志        /// </summary>        /// <param name="message"></param>        public void WriteLog(string message)        {            if (txtMsg.InvokeRequired)            {                txtMsg.Invoke(new Action(() =>                {                    txtMsg.Text = "";                    txtMsg.Text = (message + "\r");                }));            }            else            {                txtMsg.Text = "";                txtMsg.Text = (message + "\r");            }        }        /// <summary>        /// 启动        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        [Obsolete]        private async void btnStart_Click(object sender, EventArgs e)        {            var optionBuilder = new MqttServerOptionsBuilder()          .WithDefaultEndpointBoundIPAddress(System.Net.IPAddress.Parse(this.txtIP.Text))          .WithDefaultEndpointPort(int.Parse(this.txtPort.Text))          .WithDefaultCommunicationTimeout(TimeSpan.FromMilliseconds(5000))          .WithConnectionValidator(t =>          {              string un = "", pwd = "";              un = this.txtUname.Text;              pwd = this.txtUpwd.Text;              if (t.Username != un || t.Password != pwd)              {                  t.ReturnCode = MqttConnectReturnCode.ConnectionRefusedBadUsernameOrPassword;              }              else              {                  t.ReturnCode = MqttConnectReturnCode.ConnectionAccepted;              }          });            var option = optionBuilder.Build();            //启动            await server.StartAsync(option);            WriteLog(">>> 服务器启动成功");        }        /// <summary>        /// 停止         /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void btnStop_Click(object sender, EventArgs e)        {            if (server != null)            {                server.StopAsync();            }        }    }}

注意这个端口，帐号，密码可以自己决定，Ip地址也是。

注意这里面的代码，服务器上必须注册绑定实现的几个事件：消息接收事件，客户端连接事件，客户端断开事件，客户端订阅主题事件，客户端退订主题事件，服务端启动事件，服务端停止事件

 server.ApplicationMessageReceivedHandler = new MqttApplicationMessageReceivedHandlerDelegate(new Action<MqttApplicationMessageReceivedEventArgs>(Server_ApplicationMessageReceived));//绑定消息接收事件 server.ClientConnectedHandler = new MqttServerClientConnectedHandlerDelegate(new Action<MqttServerClientConnectedEventArgs>(Server_ClientConnected));//绑定客户端连接事件 server.ClientDisconnectedHandler = new MqttServerClientDisconnectedHandlerDelegate(new Action<MqttServerClientDisconnectedEventArgs>(Server_ClientDisconnected));//绑定客户端断开事件 server.ClientSubscribedTopicHandler = new MqttServerClientSubscribedHandlerDelegate(new Action<MqttServerClientSubscribedTopicEventArgs>(Server_ClientSubscribedTopic));//绑定客户端订阅主题事件 server.ClientUnsubscribedTopicHandler = new MqttServerClientUnsubscribedTopicHandlerDelegate(new Action<MqttServerClientUnsubscribedTopicEventArgs>(Server_ClientUnsubscribedTopic));//绑定客户端退订主题事件 server.StartedHandler = new MqttServerStartedHandlerDelegate(new Action<EventArgs>(Server_Started));//绑定服务端启动事件 server.StoppedHandler = new MqttServerStoppedHandlerDelegate(new Action<EventArgs>(Server_Stopped));//绑定服务端停止事件

启动测试服务器

启动成功。

3、客户端创建

1、添加项目

2、添加库引用

注意这里添加的与服务器不一样，别混错了

3、UI布局

布局使用的是常规的label，textbox，button

4、控件代码

连接代码

订阅代码

发布代码

完整代码

using MQTTnet.Client.Options;using MQTTnet.Client;using MQTTnet.Extensions.ManagedClient;using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;using MQTTnet;namespace MQTTNETClientForms{    public partial class Form1 : Form    {        private IManagedMqttClient mqttClient;//客户端mqtt对象        public Form1()        {            InitializeComponent();        }        /// <summary>        /// 连接        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private async void btnConn_Click(object sender, EventArgs e)        {            var mqttClientOptions = new MqttClientOptionsBuilder()              .WithClientId(this.txtId.Text)              .WithTcpServer(this.txtIP.Text, int.Parse(this.txtPort.Text))              .WithCredentials(this.txtName.Text, this.txtUpwd.Text);            var options = new ManagedMqttClientOptionsBuilder()                        .WithAutoReconnectDelay(TimeSpan.FromSeconds(5))                        .WithClientOptions(mqttClientOptions.Build())                        .Build();            //开启            await mqttClient.StartAsync(options);        }        /// <summary>        /// 断开        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private async void btnClose_Click(object sender, EventArgs e)        {            if (mqttClient != null)            {                if (mqttClient.IsStarted)                {                    await mqttClient.StopAsync();                }                mqttClient.Dispose();            }        }        private void Form1_Load(object sender, EventArgs e)        {            var factory = new MqttFactory();            mqttClient = factory.CreateManagedMqttClient();//创建客户端对象            //绑定断开事件            mqttClient.UseDisconnectedHandler(async ee =>            {                WriteLog("与服务器之间的连接断开了，正在尝试重新连接");                // 等待 5s 时间                await Task.Delay(TimeSpan.FromSeconds(5));                try                {                    mqttClient.UseConnectedHandler(tt =>                    {                        WriteLog(">>> 连接到服务成功");                    });                }                catch (Exception ex)                {                    WriteLog($"重新连接服务器失败:{ex}");                }            });            //绑定接收事件            mqttClient.UseApplicationMessageReceivedHandler(aa =>            {                try                {                    string msg = aa.ApplicationMessage.ConvertPayloadToString();                    WriteLog(">>> 消息：" + msg + "，QoS =" + aa.ApplicationMessage.QualityOfServiceLevel + "，客户端=" + aa.ClientId + "，主题：" + aa.ApplicationMessage.Topic);                }                catch (Exception ex)                {                    WriteLog($"+ 消息 = " + ex.Message);                }            });            //绑定连接事件            mqttClient.UseConnectedHandler(ee =>            {                WriteLog(">>> 连接到服务成功");            });        }        /// <summary>        /// 显示日志        /// </summary>        /// <param name="message"></param>        private void WriteLog(string message)        {            if (txtMsg.InvokeRequired)            {                txtMsg.Invoke(new Action(() =>                {                    txtMsg.Text = (message);                }));            }            else            {                txtMsg.Text = (message);            }        }        /// <summary>        /// 订阅        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        [Obsolete]        private async void btnSub_Click(object sender, EventArgs e)        {            if (string.IsNullOrWhiteSpace(this.txtTopic.Text))            {                WriteLog(">>> 请输入主题");                return;            }            //在 MQTT 中有三种 QoS 级别：             //At most once(0) 最多一次            //At least once(1) 至少一次            //Exactly once(2) 恰好一次            //await mqttClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(this.tbTopic.Text).WithAtMostOnceQoS().Build());//最多一次， QoS 级别0            await mqttClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(this.txtTopic.Text).WithAtLeastOnceQoS().Build());//恰好一次， QoS 级别1             WriteLog($">>> 成功订阅");        }        /// <summary>        /// 发布        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private async void btnPub_Click(object sender, EventArgs e)        {            if (string.IsNullOrWhiteSpace(this.txtTopik.Text))            {                WriteLog(">>> 请输入主题");                return;            }            var result = await mqttClient.PublishAsync(                this.txtTopik.Text,                this.txtContent.Text,                MQTTnet.Protocol.MqttQualityOfServiceLevel.AtLeastOnce);//恰好一次， QoS 级别1               WriteLog($">>> 主题：{this.txtTopik.Text}，消息：{this.txtContent.Text}，结果： {result.ReasonCode}");        }    }}