C#程式碼實現阿里雲訊息服務MNS訊息監聽

阿新 • • 發佈：2020-08-13

十年河東，十年河西，莫欺少年窮

學無止境，精益求精

近幾天一直都在看阿里雲的IOT雲服務及訊息佇列MNS，一頭霧水好幾天了，直到今天，總算有點收穫了，記錄下來，方便以後查閱。

首先借用阿里雲的一張圖來說明：裝置是如何通過雲服務平臺和企業伺服器‘通話的’

針對此圖，作如下說明：

1、物聯網平臺作為中間元件，主要是通過訊息隊MNS列來實現裝置和企業伺服器對話的，具體可描述為：

1.1、裝置傳送指令至物聯網平臺的MNS佇列，MNS佇列將裝置指令收錄，需要說明的是：裝置傳送指令是通過嵌入式開發人員開發的，例如C語言

1.2、企業通過C#、JAVA、PHP等高階語言開發人員開發監聽程式，當監聽到MNS佇列中的裝置指令時，獲取指令，做相關業務處理，併發送新的裝置指令至MNS佇列。【例如傳送快遞櫃關門的指令】

1.3、企業傳送的指令被MNS收錄，裝置同樣通過監聽程式獲取企業伺服器傳送的關門指令，收到關門指令的裝置執行相關指令，完成自動關門操作。

以上便是裝置與企業伺服器之間的對話過程

下面列出C#的監聽MNS程式碼【需要MNS C# JDK 的支援】

using Aliyun.MNS;
using Aliyun.MNS.Model;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

 
namespace MnsListener
{
    class Program
    {
        #region Private Properties
        private const string _accessKeyId = "MNS的keyID";
        private const string _secretAccessKey = "MNS的_secretAccessKey";
        private const string _endpoint = "MNS的URL";
        private const string _stsToken = null 
;

        private const string _queueName = "Sub";
        private const string _queueNamePrefix = "my";
        private const int _receiveTimes = 1;
        private const int _receiveInterval = 2;
        private const int batchSize = 6;
        private static string _receiptHandle;

        #endregion


        static void Main(string[] args)
        {
            while (true)
            {
                try
                {
                    IMNS client = new Aliyun.MNS.MNSClient(_accessKeyId, _secretAccessKey, _endpoint, _stsToken);
                    var nativeQueue = client.GetNativeQueue(_queueName);
                    for (int i = 0; i < _receiveTimes; i++)
                    {
                        var receiveMessageResponse = nativeQueue.ReceiveMessage(3);
                        Console.WriteLine("Receive message successfully, status code: {0}", receiveMessageResponse.HttpStatusCode);
                        Console.WriteLine("----------------------------------------------------");
                        Message message = receiveMessageResponse.Message;
                        Console.WriteLine("MessageId: {0}", message.Id);
                        Console.WriteLine("ReceiptHandle: {0}", message.ReceiptHandle);
                        Console.WriteLine("MessageBody: {0}", message.Body);
                        Console.WriteLine("MessageBodyMD5: {0}", message.BodyMD5);
                        Console.WriteLine("EnqueueTime: {0}", message.EnqueueTime);
                        Console.WriteLine("NextVisibleTime: {0}", message.NextVisibleTime);
                        Console.WriteLine("FirstDequeueTime: {0}", message.FirstDequeueTime);
                        Console.WriteLine("DequeueCount: {0}", message.DequeueCount);
                        Console.WriteLine("Priority: {0}", message.Priority);
                        Console.WriteLine("----------------------------------------------------\n");

                        _receiptHandle = message.ReceiptHandle;
                        nativeQueue.DeleteMessage(_receiptHandle);

                        Thread.Sleep(_receiveInterval);
                    }
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Receive message failed, exception info: " + ex.Message);
                }
            }

        }
    }
}