.net mqtt common class library 2, m2mqtt two libraries and mqttnet
Of course, these two libraries tutorials online search a lot
But mqttnet to search the full tutorial is version 2.7 and below, but the syntax is no longer compatible with version 3.0, the upgrade version will lead to many problems, has been upgraded successful today, is recorded
Reference Document address: https: //github.com/chkr1011/MQTTnet/wiki/Client
On the code:
1 ///开源库地址：https://github.com/chkr1011/MQTTnet 2 ///对应文档：https://github.com/chkr1011/MQTTnet/wiki/Client 3 4 using MQTTnet; 5 using MQTTnet.Client; 6 using MQTTnet.Client.Options; 7 using System; 8 using System.Text; 9 using System.Threading; 10 using System.Threading.Tasks; 11 using System.Windows.Forms; 12 13 namespace MqttServerTest 14 { 15 public partial class MQTT test tools: Form1 16 { . 17 Private IMqttClient mqttClient = null ; 18 is Private BOOL isReconnect = to true ; . 19 20 is public MQTT test tool () 21 is { 22 is the InitializeComponent (); 23 is } 24 25 Private void the Form1_Load ( Object SENDER , EventArgs E) 26 is { 27 28 } 29 30 private async void BtnPublish_Click(object sender, EventArgs e) 31 { 32 await Publish(); 33 } 34 35 private async void BtnSubscribe_ClickAsync(object sender, EventArgs e) 36 { 37 await Subscribe(); 38 } 39 40 private async Task Publish() 41 { 42 string topic = txtPubTopic.Text.Trim(); 43 44 if (string.IsNullOrEmpty(topic)) 45 { 46 MessageBox.Show("发布主题不能为空！"); 47 return; 48 } 49 50 string inputString = txtSendMessage.Text.Trim(); 51 try 52 { 53 54 var message = new MqttApplicationMessageBuilder() 55 .WithTopic(topic) 56 .WithPayload(inputString) 57 .WithExactlyOnceQoS() 58 .WithRetainFlag() 59 .Build(); 60 61 await mqttClient.PublishAsync(message); 62 } 63 catch (Exception ex) 64 { 65 66 Invoke((new Action(() => 67 { 68 txtReceiveMessage.AppendText($"发布主题失败！" + Environment.NewLine + ex.Message + Environment.NewLine); 69 }))); 70 } 71 72 73 is 74 75 } 76 77 Private the async the Task the Subscribe () 78 { 79 String Topic = txtSubTopic.Text.Trim (); 80 81 IF ( String .IsNullOrEmpty (Topic)) 82 { 83 MessageBox.Show ( " subscribe topic can not be empty ! " ); 84 return ; 85 } 86 87 IF ! ( mqttClient.IsConnected) 88 { 89 MessageBox.Show("MQTT客户端尚未连接！"); 90 return; 91 } 92 93 // Subscribe to a topic 94 await mqttClient.SubscribeAsync(new TopicFilterBuilder() 95 .WithTopic(topic) 96 .WithAtMostOnceQoS() 97 .Build() 98 ); 99 Invoke((new Action(() => 100 { 101 txtReceiveMessage.AppendText($"已订阅[{topic}]主题{Environment.NewLine}"); 102 }))); 103 104 } 105 106 private async Task ConnectMqttServerAsync() 107 { 108 // Create a new MQTT client. 109 110 if (mqttClient == null) 111 { 112 try 113 { 114 var factory = new MqttFactory(); 115 mqttClient = factory.CreateMqttClient(); 116 117 var options = new MqttClientOptionsBuilder() 118 .WithTcpServer(txtIp.Text, Convert.ToInt32(txtPort.Text)).WithCredentials(txtUsername.Text, txtPsw.Text).WithClientId(txtClientId.Text) // Port is optional 119 .Build(); 120 121 122 await mqttClient.ConnectAsync(options, CancellationToken.None); 123 Invoke((new Action(() => 124 { 125 txtReceiveMessage.AppendText($"连接到MQTT服务器成功！" + txtIp.Text); 126 }))); 127 mqttClient.UseApplicationMessageReceivedHandler(e => 128 { 129 130 Invoke((new Action(() => 131 { 132 txtReceiveMessage.AppendText($"收到订阅消息！" + Encoding.UTF8.GetString(e.ApplicationMessage.Payload)); 133 }))); 134 135 }); 136 } 137 catch(Exception EX) 138 { 139 140 the Invoke (( new new the Action (() => 141 is { 142 txtReceiveMessage.AppendText ($ " is connected to the server failed MQTT! " + Environment.NewLine ex.Message + + Environment.NewLine); 143 } ))); 144 } 145 } 146 } 147 148 Private void MqttClient_Connected ( Object SENDER, EventArgs E) 149 { 150 Invoke((new Action(() => 151 { 152 txtReceiveMessage.Clear(); 153 txtReceiveMessage.AppendText("已连接到MQTT服务器！" + Environment.NewLine); 154 }))); 155 } 156 157 private void MqttClient_Disconnected(object sender, EventArgs e) 158 { 159 Invoke((new Action(() => 160 { 161 txtReceiveMessage.Clear(); 162 DateTime curTime = new DateTime(); 163 curTime = DateTime.UtcNow; 164 txtReceiveMessage.AppendText($">> [{curTime.ToLongTimeString()}]"); 165 txtReceiveMessage.AppendText("已断开MQTT连接！" + Environment.NewLine); 166 }))); 167 168 //Reconnecting 169 if (isReconnect) 170 { 171 Invoke((new Action(() => 172 { 173 txtReceiveMessage.AppendText("正在尝试重新连接" + Environment.NewLine); 174 }))); 175 176 var options = new MqttClientOptionsBuilder() 177 .WithClientId(txtClientId.Text) 178 .WithTcpServer(txtIp.Text, Convert.ToInt32(txtPort.Text)) 179 .WithCredentials(txtUsername.Text, txtPsw.Text) 180 //.WithTls() 181 .WithCleanSession() 182 .Build(); 183 Invoke((new Action(async () => 184 { 185 await Task.Delay(TimeSpan.FromSeconds(5)); 186 try 187 { 188 await mqttClient.ConnectAsync(options); 189 } 190 catch 191 { 192 txtReceiveMessage.AppendText("### RECONNECTING FAILED ###" + Environment.NewLine); 193 } 194 }))); 195 } 196 else 197 { 198 Invoke((new Action(() => 199 { 200 txtReceiveMessage.AppendText("已下线！" + Environment.NewLine); 201 }))); 202 } 203 } 204 205 private void MqttClient_ApplicationMessageReceived(object sender, MqttApplicationMessageReceivedEventArgs e) 206 { 207 Invoke((new Action(() => 208 { 209 txtReceiveMessage.AppendText($">> {"### RECEIVED APPLICATION MESSAGE ###"}{Environment.NewLine}"); 210 }))); 211 Invoke((new Action(() => 212 { 213 txtReceiveMessage.AppendText($">> Topic = {e.ApplicationMessage.Topic}{Environment.NewLine}"); 214 }))); 215 Invoke((new Action(() => 216 { 217 txtReceiveMessage.AppendText($">> Payload = {Encoding.UTF8.GetString(e.ApplicationMessage.Payload)}{Environment.NewLine}"); 218 }))); 219 Invoke((new Action(() => 220 { 221 txtReceiveMessage.AppendText($">> QoS = {e.ApplicationMessage.QualityOfServiceLevel}{Environment.NewLine}"); 222 }))); 223 Invoke((new Action(() => 224 { 225 txtReceiveMessage.AppendText($">> Retain = {e.ApplicationMessage.Retain}{Environment.NewLine}"); 226 }))); 227 } 228 229 private void btnLogIn_Click(object sender, EventArgs e) 230 { 231 isReconnect = true; 232 Task.Run(async () => { await ConnectMqttServerAsync(); }); 233 } 234 235 private void btnLogout_Click(object sender, EventArgs e) 236 { 237 isReconnect = false; 238 Task.Run(async () => { await mqttClient.DisconnectAsync(); }); 239 } 240 241 } 242 }