.NET Core 跨平臺物聯網開發：設置委託事件(二)

系列教程目錄

 (一) 鏈接阿里雲IOT

 (二) 設置委託事件

 (三) 上報屬性

 (四)  SDK文檔 屬性、方法、委託、類

 http://pan.whuanle.cn/index.php?dir=uploads/阿里雲IOT/AliIOTXFclient-dll類庫&response

下載三個庫，頭部引入 便可使用

using AliIOTXFClient;

示例下載地址

http://pan.whuanle.cn/index.php?dir=uploads/阿里雲IOT/demo示例

本章示例 AliIOTXF.Twe

生命週期

 

事件類型

目前只設置了五個委託事件

XFMQTT.ConnectionClosedEventHandler 
XFMQTT.PubedEventHandler
XFMQTT.PubEventHandler
XFMQTT.SubedEventHandler
XFMQTT.UnSubedEventHandler

委託	說明
XFMQTT.PubEventHandler	訂閱回調 - 當收到服務器消息時
XFMQTT.PubedEventHandler	當 QOS=1或2時，收到訂閱觸發
XFMQTT.SubedEventHandler	向服務器發佈 Topic 時
XFMQTT.SubedEventHandler	向服務器發佈 Topic 失敗時
XFMQTT.ConnectionClosedEventHandler	斷開鏈接

MQTT是一種可靠的消息推送協議，QOS保證了消息必須完整地推送給另外一端，關於QOS具體能夠百度~

• QOS = 0 ，最多一次
• QOS = 1，至少一次
• QOS = 2，只有一次

表明消息推送地可靠程度，當 QOS = 1是，在網絡波動等狀況下，可能會存在屢次重複的一次推送。

 

使用默認的委託方法：

            // 使用默認的委託事件
            client.UseDefaultEventHandler();

 經過上一篇文章，程序已經能夠運行、鏈接到阿里雲服務器，而且能夠訂閱發佈消息。

這些操做都會觸發事件，經過 UseDefaultEventHandler() 方法，使用的默認的方法綁定到事件。

自定義事件方法

刪除 這一行代碼

client.UseDefaultEventHandler();

頭部引入

using uPLibrary.Networking.M2Mqtt.Messages;

注意，這五個委託方法的參數是不同的。 

 

XFMQTT.PubEventHandler

訂閱回調 - 當收到服務器消息時觸發

委託方法以下

         委託方法(object sender, MqttMsgPublishEventArgs e)
        {

        }

MqttMsgPublishEventArgs 是與接收消息有關的對象，其屬性以下：

        // message topic
        private string topic;
        // message data
        private byte[] message;
        // duplicate delivery
        private bool dupFlag;
        // quality of service level
        private byte qosLevel;
        // retain flag
        private bool retain;   

SDK 默認的委託方法

        public void Default_PubEventHandler(object sender, MqttMsgPublishEventArgs e)
        {
            // handle message received
            string topic = e.Topic;
            string message = Encoding.ASCII.GetString(e.Message);
            Console.WriteLine("- - - - - - - - - - ");
            Console.WriteLine("get topic message,Date: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("topic: " + topic);
            Console.WriteLine("get messgae :\n" + message);
        }

那麼咱們來寫一個自定義委託方法

裏面的怎麼寫都行，方法名稱隨意

        public static void 收到消息(object sender, MqttMsgPublishEventArgs e)
        {
            Console.WriteLine("topic名稱："+e.Topic);
            Console.WriteLine("接收時間：" + DateTime.Now.ToLongDateString());
            Console.WriteLine("消息內容：\n"+Encoding.ASCII.GetString(e.Message));
        }

在刪除 client.UseDefaultEventHandler(); 的位置加上

client.PubEventHandler += 收到消息;

XFMQTT.PubedEventHandler

當 QOS=1或2時，收到訂閱觸發

原型

委託方法(object sender, MqttMsgPublishedEventArgs e)
    {

    }

 MqttMsgPublishedEventArgs 屬性

        // message identifier
        ushort messageId;

        // published flag
        bool isPublished;

SDK 默認方法

        public void Default_PubedEventHandler(object sender, MqttMsgPublishedEventArgs e)
        {
            Console.WriteLine("- - - - - - - - - - ");
            Console.WriteLine("published,Date: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("MessageId: " + e.MessageId + "    Is Published: " + e.IsPublished);
        }

咱們來自定義寫，方法名稱隨意

        public static void 重複收到消息(object sender, MqttMsgPublishedEventArgs e)
        {
            Console.WriteLine("接收時間: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("消息id: " + e.MessageId + "    Is Published: " + e.IsPublished);
        }

加上

client.PubedEventHandler += 重複收到消息;

 

XFMQTT.SubedEventHandler

向服務器發佈 Topic 時觸發

原型

void 發佈消息時(object sender, MqttMsgSubscribedEventArgs e)

MqttMsgSubscribedEventArgs 屬性

        /// <summary>
        /// Message identifier
        /// </summary>
        public ushort MessageId {get;set;}

        /// <summary>
        /// List of granted QOS Levels
        /// </summary>
        public byte[] GrantedQoSLevels{get;set;}

        // message identifier
        ushort messageId;
        // granted QOS levels
        byte[] grantedQosLevels;

SDK 默認寫法

        public void Default_SubedEventHandler(object sender, MqttMsgSubscribedEventArgs e)
        {
            Console.WriteLine("- - - - - - - - - - ");
            Console.WriteLine("Sub topic,Date: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("MessageId: " + e.MessageId);
            Console.WriteLine("List of granted QOS Levels:    " + Encoding.UTF8.GetString(e.GrantedQoSLevels));
        }

咱們來自定義寫，方法名稱隨意

        public static void 發佈消息時(object sender, MqttMsgSubscribedEventArgs e)
        {
            Console.WriteLine("向服務器發送了消息");
            Console.WriteLine("發送時間: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("消息id: " + e.MessageId);
            Console.WriteLine("QOS 爲 :    " + Encoding.UTF8.GetString(e.GrantedQoSLevels));
        }

加上

client.SubedEventHandler += 發佈消息時;

 

XFMQTT.UnSubedEventHandler

向服務器發佈 Topic 失敗時觸發

void 發送失敗(object sender, MqttMsgUnsubscribedEventArgs )
{

}

MqttMsgUnsubscribedEventArgs 屬性

        /// <summary>
        /// Message identifier
        /// </summary>
        public ushort MessageId
        {
            get { return this.messageId; }
            internal set { this.messageId = value; }
        }

SDK 寫法

        public void Default_UnSubedEventHandler(object sender, MqttMsgUnsubscribedEventArgs e)
        {
            Console.WriteLine("- - - - - - - - - - ");
            Console.WriteLine("Sub topic error,Date: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("MessageId:    " + e.MessageId);
        }

 

咱們自定義寫

        public static void 發送失敗(object sender, MqttMsgUnsubscribedEventArgs e)
        {
            Console.WriteLine("消息發送失敗 ");
            Console.WriteLine("時間: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("失敗的消息 MessageId:    " + e.MessageId);
        }

加上

client.UnSubedEventHandler += 發送失敗;

XFMQTT.ConnectionClosedEventHandler

斷開鏈接時觸發

 SDK 寫法

        public void Default_ConnectionClosedEventHandler(object sender, EventArgs e)
        {
            Console.WriteLine("- - - - - - - - - - ");
            Console.WriteLine("Connect Closed error,Date: " + DateTime.Now.ToLongTimeString());
        }

自定義寫

        public static void 斷開鏈接(object sender, EventArgs e)
        {
            Console.WriteLine("日。。。鏈接斷開了: " + DateTime.Now.ToLongTimeString());
        }

加上

client.ConnectionClosedEventHandler += 斷開鏈接;

 

完整代碼

        static void Main(string[] args)
        {
            // 建立鏈接對象
            XFMQTT client = new XFMQTT("a1BiPoNawLI", "Raspberry");
            // 初始化客戶端配置
            client.Init("2NOaBeqXcIzLQEhlJFEfKbWeug0o3m0c", "cn-shanghai");
            // 要訂閱的Topic
            string[] topic = { client.CombineHeadTopic("PubData") };

            // 使用自定義的委託事件
            client.PubEventHandler += 收到消息;
            client.PubedEventHandler += 重複收到消息;
            client.SubedEventHandler += 發佈消息時;
            client.UnSubedEventHandler += 發送失敗;
            client.ConnectionClosedEventHandler += 斷開鏈接;
            // 鏈接服務器
            client.ConnectMqtt(topic);

            while (true)
            {
                string str = Console.ReadLine();

                // 推送內容到特定的 Topic
                client.Subscribe(client.CombineHeadTopic("SubData"), str);
            }

            Console.ReadKey();
        }
        public static void 收到消息(object sender, MqttMsgPublishEventArgs e)
        {
            Console.WriteLine("topic名稱："+e.Topic);
            Console.WriteLine("接收時間：" + DateTime.Now.ToLongDateString());
            Console.WriteLine("消息內容：\n"+Encoding.ASCII.GetString(e.Message));
        }
        public static void 重複收到消息(object sender, MqttMsgPublishedEventArgs e)
        {
            Console.WriteLine("接收時間: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("消息id: " + e.MessageId + "    Is Published: " + e.IsPublished);
        }
        public static void 發佈消息時(object sender, MqttMsgSubscribedEventArgs e)
        {
            Console.WriteLine("向服務器發送了消息");
            Console.WriteLine("發送時間: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("消息id: " + e.MessageId);
            Console.WriteLine("QOS 爲 :    " + Encoding.UTF8.GetString(e.GrantedQoSLevels));
        }
        public static void 發送失敗(object sender, MqttMsgUnsubscribedEventArgs e)
        {
            Console.WriteLine("消息發送失敗 ");
            Console.WriteLine("時間: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("失敗的消息 MessageId:    " + e.MessageId);
        }
        public static void 斷開鏈接(object sender, EventArgs e)
        {
            Console.WriteLine("日。。。鏈接斷開了: " + DateTime.Now.ToLongTimeString());
        }

可是這樣子很差，換種寫法

    class Program
    {
        static void Main(string[] args)
        {
            // 建立鏈接對象
            XFMQTT client = new XFMQTT("a1BiPoNawLI", "Raspberry");
            // 初始化客戶端配置
            client.Init("2NOaBeqXcIzLQEhlJFEfKbWeug0o3m0c", "cn-shanghai");
            // 要訂閱的Topic
            string[] topic = { client.CombineHeadTopic("PubData") };

            // 使用自定義的委託事件
            事件類 事件 = new 事件類();
            client.PubEventHandler += 事件.收到消息;
            client.PubedEventHandler += 事件.重複收到消息;
            client.SubedEventHandler += 事件.發佈消息時;
            client.UnSubedEventHandler += 事件.發送失敗;
            client.ConnectionClosedEventHandler += 事件.斷開鏈接;
            // 鏈接服務器
            client.ConnectMqtt(topic);

            while (true)
            {
                string str = Console.ReadLine();

                // 推送內容到特定的 Topic
                client.Subscribe(client.CombineHeadTopic("SubData"), str);
            }

            Console.ReadKey();
        }
    }
    public class 事件類
    {
        public  void 收到消息(object sender, MqttMsgPublishEventArgs e)
        {
            Console.WriteLine("topic名稱：" + e.Topic);
            Console.WriteLine("接收時間：" + DateTime.Now.ToLongDateString());
            Console.WriteLine("消息內容：\n" + Encoding.ASCII.GetString(e.Message));
        }
        public  void 重複收到消息(object sender, MqttMsgPublishedEventArgs e)
        {
            Console.WriteLine("接收時間: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("消息id: " + e.MessageId + "    Is Published: " + e.IsPublished);
        }
        public void 發佈消息時(object sender, MqttMsgSubscribedEventArgs e)
        {
            Console.WriteLine("向服務器發送了消息");
            Console.WriteLine("發送時間: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("消息id: " + e.MessageId);
            Console.WriteLine("QOS 爲 :    " + Encoding.UTF8.GetString(e.GrantedQoSLevels));
        }
        public void 發送失敗(object sender, MqttMsgUnsubscribedEventArgs e)
        {
            Console.WriteLine("消息發送失敗 ");
            Console.WriteLine("時間: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("失敗的消息 MessageId:    " + e.MessageId);
        }
        public  void 斷開鏈接(object sender, EventArgs e)
        {
            Console.WriteLine("日。。。鏈接斷開了: " + DateTime.Now.ToLongTimeString());
        }
    }

 

使用默認事件方法與自定義事件方法並不衝突。

 

 // 使用默認事件方法
            client.UseDefaultEventHandler();
            // 使用自定義的委託事件
            事件類 事件 = new 事件類();
            client.PubEventHandler += 事件.收到消息;
            client.PubedEventHandler += 事件.重複收到消息;
            client.SubedEventHandler += 事件.發佈消息時;
            client.UnSubedEventHandler += 事件.發送失敗;
            client.ConnectionClosedEventHandler += 事件.斷開鏈接;

 

爲便於理解，上面事件方法使用了中文名稱，請根據實際修改。