C#编写上位机连接华为云平台IoTDA
Posted 跋扈洋
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C#连接华为云平台IoTDA
需求
我们在平时的物联网开发中，往往需要用到云平台来收发数据。而光有云平台往往是不行的，我们还需要有上位机。那么怎样通过上位机连接到云平台，并且收发数据呢？本文将介绍如何通过C#编写的上位机和华为云平台通过物联网最常用MQTT协议进行连接并收发数据。介绍设备通MQTTS/MQTT协议接入平台，通过平台接口实现“数据上报”、“命令下发”的功能。
前期准备
- VS2019
- 华为云平台
具体设计
代码目录简述：
- App.config：Server地址和设备信息配置文件
- C#：项目C#代码；
- EncryptUtil.cs：设备密钥加密辅助类；
- FrmMqttDemo.cs：窗体界面；
- Program.cs：Demo程序启动入口。
- dll：项目中使用到了第三方库
- MQTTnet：v3.0.11，是一个基于 MQTT 通信的高性能 .NET 开源库，它同时支持MQTT 服务器端和客户端，引用库文件包含MQTTnet.dll。
- MQTTnet.Extensions.ManagedClient：v3.0.11，这是一个扩展库，它使用MQTTnet为托管MQTT客户机提供附加功能。
工程配置参数
App.config：需要配置服务器地址、设备ID和设备密钥，用于启动Demo程序的时
候，程序将此信息自动写到Demo主界面。
<add key="serverUri" value="serveruri"/>
<add key="deviceId" value="deviceid"/>
<add key="deviceSecret" value="secret"/>
<add key="PortIsSsl" value="8883"/>
<add key="PortNotSsl" value="1883"/>
具体程序
App.config
本文件中存放的是Server地址和设备信息配置文件，我们每个人的程序主要的不同就是这个文件，虽然后面也可以在运行的时候改，但最好提前写入。
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
</configSections>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2"/>
</startup>
<appSettings>
<add key="serverUri" value="iot-mqtts.cn-north-4.myhuaweicloud.com"/>
<add key="deviceId" value="自己的设备ID"/>
<add key="deviceSecret" value="自己的设备密钥"/>
<add key="portIsSsl" value="8883"/>
<add key="portNotSsl" value="1883"/>
<add key="language" value="zh-CN"/>
</appSettings>
</configuration>
我们将自己的自己的设备ID和自己的设备密钥填入其中，选择相应的语言，最好填中文，毕竟看的方便。
主程序
连接服务器
try
int portIsSsl = int.Parse(ConfigurationManager.AppSettings["portIsSsl"]);
int portNotSsl = int.Parse(ConfigurationManager.AppSettings["portNotSsl"]);
if (client == null)
client = new MqttFactory().CreateManagedMqttClient();
string timestamp = DateTime.Now.ToString("yyyyMMddHH");
string clientID = txtDeviceId.Text + "_0_0_" + timestamp;
// 对密码进行HmacSHA256加密
string secret = string.Empty;
if (!string.IsNullOrEmpty(txtDeviceSecret.Text))
secret = EncryptUtil.HmacSHA256(txtDeviceSecret.Text, timestamp);
// 判断是否为安全连接
if (!cbSSLConnect.Checked)
options = new ManagedMqttClientOptionsBuilder()
.WithAutoReconnectDelay(TimeSpan.FromSeconds(RECONNECT_TIME))
.WithClientOptions(new MqttClientOptionsBuilder()
.WithTcpServer(txtServerUri.Text, portNotSsl)
.WithCommunicationTimeout(TimeSpan.FromSeconds(DEFAULT_CONNECT_TIMEOUT))
.WithCredentials(txtDeviceId.Text, secret)
.WithClientId(clientID)
.WithKeepAlivePeriod(TimeSpan.FromSeconds(DEFAULT_KEEPLIVE))
.WithCleanSession(false)
.WithProtocolVersion(MqttProtocolVersion.V311)
.Build())
.Build();
else
string caCertPath = Environment.CurrentDirectory + @"\\certificate\\rootcert.pem";
X509Certificate2 crt = new X509Certificate2(caCertPath);
options = new ManagedMqttClientOptionsBuilder()
.WithAutoReconnectDelay(TimeSpan.FromSeconds(RECONNECT_TIME))
.WithClientOptions(new MqttClientOptionsBuilder()
.WithTcpServer(txtServerUri.Text, portIsSsl)
.WithCommunicationTimeout(TimeSpan.FromSeconds(DEFAULT_CONNECT_TIMEOUT))
.WithCredentials(txtDeviceId.Text, secret)
.WithClientId(clientID)
.WithKeepAlivePeriod(TimeSpan.FromSeconds(DEFAULT_KEEPLIVE))
.WithCleanSession(false)
.WithTls(new MqttClientOptionsBuilderTlsParameters()
AllowUntrustedCertificates = true,
UseTls = true,
Certificates = new List<X509Certificate> crt ,
CertificateValidationHandler = delegate return true; ,
IgnoreCertificateChainErrors = false,
IgnoreCertificateRevocationErrors = false
)
.WithProtocolVersion(MqttProtocolVersion.V311)
.Build())
.Build();
Invoke((new Action(() =>
ShowLogs($""try to connect to server " + txtServerUri.TextEnvironment.NewLine");
)));
if (client.IsStarted)
await client.StopAsync();
// 注册事件
client.ApplicationMessageProcessedHandler = new ApplicationMessageProcessedHandlerDelegate(new Action<ApplicationMessageProcessedEventArgs>(ApplicationMessageProcessedHandlerMethod)); // 消息发布回调
client.ApplicationMessageReceivedHandler = new MqttApplicationMessageReceivedHandlerDelegate(new Action<MqttApplicationMessageReceivedEventArgs>(MqttApplicationMessageReceived)); // 命令下发回调
client.ConnectedHandler = new MqttClientConnectedHandlerDelegate(new Action<MqttClientConnectedEventArgs>(OnMqttClientConnected)); // 连接成功回调
client.DisconnectedHandler = new MqttClientDisconnectedHandlerDelegate(new Action<MqttClientDisconnectedEventArgs>(OnMqttClientDisconnected)); // 连接断开回调
// 连接平台设备
await client.StartAsync(options);
catch (Exception ex)
Invoke((new Action(() =>
ShowLogs($"connect to mqtt server fail" + Environment.NewLine);
)));
接收到消息
Invoke((new Action(() =>
ShowLogs($"received message is Encoding.UTF8.GetString(e.ApplicationMessage.Payload)Environment.NewLine");
string msg = "\\"result_code\\": 0,\\"response_name\\": \\"COMMAND_RESPONSE\\",\\"paras\\": \\"result\\": \\"success\\"";
string topic = "$oc/devices/" + txtDeviceId.Text + "/sys/commands/response/request_id=" + e.ApplicationMessage.Topic.Split('=')[1];
ShowLogs($""response message msg = " + msgEnvironment.NewLine");
var appMsg = new MqttApplicationMessage();
appMsg.Payload = Encoding.UTF8.GetBytes(msg);
appMsg.Topic = topic;
appMsg.QualityOfServiceLevel = int.Parse(cbOosSelect.SelectedValue.ToString()) == 0 ? MqttQualityOfServiceLevel.AtMostOnce : MqttQualityOfServiceLevel.AtLeastOnce;
appMsg.Retain = false;
// 上行响应
client.PublishAsync(appMsg).Wait();
)));
消息发布回调
try
if (e.HasFailed)
Invoke((new Action(() =>
ShowLogs("publish messageId is " + e.ApplicationMessage.Id + ", topic: " + e.ApplicationMessage.ApplicationMessage.Topic + ", payload: " + Encoding.UTF8.GetString(e.ApplicationMessage.ApplicationMessage.Payload) + " is published fail");
)));
else if (e.HasSucceeded)
Invoke((new Action(() =>
ShowLogs("publish messageId " + e.ApplicationMessage.Id + ", topic: " + e.ApplicationMessage.ApplicationMessage.Topic + ", payload: " + Encoding.UTF8.GetString(e.ApplicationMessage.ApplicationMessage.Payload) + " is published success");
)));
catch (Exception ex)
Invoke((new Action(() =>
ShowLogs("mqtt demo message publish error: " + ex.Message + Environment.NewLine);
)));
服务器连接成功
Invoke((new Action(() =>
ShowLogs("connect to mqtt server success, deviceId is " + txtDeviceId.Text + Environment.NewLine);
btnConnect.Enabled = false;
btnDisconnect.Enabled = true;
btnPublish.Enabled = true;
btnSubscribe.Enabled = true;
)));
断开服务器连接
try
Invoke((new Action(() =>
ShowLogs("mqtt server is disconnected" + Environment.NewLine);
txtSubTopic.Enabled = true;
btnConnect.Enabled = true;
btnDisconnect.Enabled = false;
btnPublish.Enabled = false;
btnSubscribe.Enabled = false;
)));
if (cbReconnect.Checked)
Invoke((new Action(() =>
ShowLogs("reconnect is starting" + Environment.NewLine);
)));
//退避重连
int lowBound = (int)(defaultBackoff * 0.8);
int highBound = (int)(defaultBackoff * 1.2);
long randomBackOff = random.Next(highBound - lowBound);
long backOffWithJitter = (int)(Math.Pow(2.0, retryTimes)) * (randomBackOff + lowBound);
long waitTImeUtilNextRetry = (int)(minBackoff + backOffWithJitter) > maxBackoff ? maxBackoff : (minBackoff + backOffWithJitter);
Invoke((new Action(() =>
ShowLogs("next retry time: " + waitTImeUtilNextRetry + Environment.NewLine);
)));
Thread.Sleep((int)waitTImeUtilNextRetry);
retryTimes++;
Task.Run(async () => await ConnectMqttServerAsync(); );
catch (Exception ex)
Invoke((new Action(() =>
ShowLogs("mqtt demo error: " + ex.Message + Environment.NewLine);
)));
格式
设备端上传到云平台
Topic：$oc/devices/device_id/sys/properties/report
数据格式：
数据格式：
"services": [
"service_id": "Temperature",
"properties":
"smoke": 57,
"temperature": 60,
"humidity":78.37673
,
"event_time": "20151212T121212Z"
]
运行界面
当我发送如下数据时：
"services": [
"service_id": "BS",
"properties":
"smoke": 57,
"temperature": 60,
"humidity":78.37673
,
"event_time": "20151212T121212Z"
]
后续
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