C# 基于开源MQTT自主接入阿里云IoT平台

1. 准备工作

1.1 注册阿里云账号

使用淘宝账号或手机号，开通阿里云账号，并通过实名认证(可以用支付宝认证)

1.2 免费开通IoT物联网套件

产品官网 https://www.aliyun.com/product/iot

1.3 软件开发环境

语言 C#
工具 Visual Studio IDE

2. IoT平台云端开发

2.1 创建基础版产品

产品信息

消息通信Topic

2.2 注册设备

获取设备身份三元组，ProductKey，DeviceName，DeviceSecret

3. 设备端开发

3.1 IoT平台接入password签名算法文件

签名规则参考 https://www.yuque.com/cloud-dev/iot-tech/mebm5g

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
namespace iotxsdkmqttnet {public class IotSignUtils {public static string sign(Dictionary<string, string> param, string deviceSecret, string signMethod) {string[] sortedKey = param.Keys.ToArray();Array.Sort(sortedKey);StringBuilder builder = new StringBuilder();foreach(var i in sortedKey){builder.Append(i).Append(param[i]);}byte[] key = Encoding.UTF8.GetBytes(deviceSecret);byte[] signContent = Encoding.UTF8.GetBytes(builder.ToString());//根据signMethod动态调整，硬编码了： 'hmacmd5'var hmac = new HMACMD5(key);byte[] hashBytes = hmac.ComputeHash(signContent);StringBuilder signBuilder = new StringBuilder();foreach (byte b in hashBytes)signBuilder.AppendFormat("{0:x2}", b);return signBuilder.ToString();}}
}

3.2 接入IoT平台C#版本的MQTT库

C#的mqtt库 https://www.nuget.org/packages/M2Mqtt/

目前最好用的C#库是 eclipse出的M2Mqtt库，

主页链接： http://www.eclipse.org/paho/clients/dotnet/

项目的地址是 https://github.com/eclipse/paho.mqtt.m2mqtt

使用方式是在vs 的命令中输入 Install-Package M2Mqtt

组件下载：M2Mqtt.Net.dll （v4.3.0最新版 2019.7.16本地生成）

链接：https://pan.baidu.com/s/1lacs13v9nde8d2wrj2oU4g
提取码：l8cg

3.3 设备端应用程序

using System;
using System.Net;
using System.Collections.Generic;
using uPLibrary.Networking.M2Mqtt;
using uPLibrary.Networking.M2Mqtt.Messages;
using System.Text;
using System.Linq;namespace iotMqttDemo {class MainClass {static string ProductKey = "******";static string DeviceName = "******";static string DeviceSecret = "******";static string RegionId = "cn-shanghai";static string PubTopic = "/" + ProductKey + "/" + DeviceName + "/update";static string SubTopic = "/" + ProductKey + "/" + DeviceName + "/get";public static void Main(string[] args){IPHostEntry host = Dns.GetHostEntry(Dns.GetHostName());string clientId = host.AddressList.FirstOrDefault(ip => ip.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork).ToString();string t = Convert.ToString(DateTimeOffset.Now.ToUnixTimeMilliseconds());string signmethod = "hmacmd5";Dictionary<string, string> dict = new Dictionary<string, string>();dict.Add("productKey", ProductKey);dict.Add("deviceName", DeviceName);dict.Add("clientId", clientId);dict.Add("timestamp", t);string mqttUserName = DeviceName + "&" + ProductKey;string mqttPassword = IotSignUtils.sign(dict, DeviceSecret, signmethod);string mqttClientId = clientId + "|securemode=3,signmethod="+signmethod+",timestamp=" + t + "|";string targetServer = "tcp://" + ProductKey + ".iot-as-mqtt." + RegionId + ".aliyuncs.com";ConnectMqtt(targetServer, mqttClientId, mqttUserName, mqttPassword);}static void ConnectMqtt(string targetServer, string mqttClientId, string mqttUserName, string mqttPassword){MqttClient client = new MqttClient(targetServer);client.ProtocolVersion = MqttProtocolVersion.Version_3_1_1;client.Connect(mqttClientId, mqttUserName, mqttPassword, false, 60);client.MqttMsgPublishReceived += Client_MqttMsgPublishReceived;//发布消息String content = "{'content':'msg from :" + mqttClientId + ", 这里是.NET设备'}";var id = client.Publish(PubTopic, Encoding.ASCII.GetBytes(content));//订阅消息client.Subscribe(new string[] { SubTopic }, new byte[] { 0 });}static void Client_MqttMsgPublishReceived(object sender, MqttMsgPublishEventArgs e){// handle message receivedstring topic = e.Topic;string message = Encoding.ASCII.GetString(e.Message);}}
}

4. 运行结果

云端看到设备上线记录，数据上报记录

至此，完成了.NET平台设备C#语言接入阿里云IoT物联网云平台的开发实践。

MQTT模拟器：关注

知识课堂：C# MQTTnet使用心得和C# MQTT库M2Mqtt的使用方法

https://blog.csdn.net/uaime/article/details/96119179