.NET Core 跨平台物联网开发:设置委托事件(二)
系列教程目录
(一) 连接阿里云IOT
(二) 设置委托事件
(三) 上报属性
(四) SDK文档 属性、方法、委托、类
http://pan.whuanle.cn/index.php?dir=uploads/阿里云IOT/AliIOTXFclient-dll类库&response
下载三个库,头部引入 即可使用
using AliIOTXFClient;
示例下载地址
http://pan.whuanle.cn/index.php?dir=uploads/阿里云IOT/demo示例
本章示例 AliIOTXF.Twe
生命周期
事件类型
目前只设置了五个委托事件
XFMQTT.ConnectionClosedEventHandler
XFMQTT.PubedEventHandler
XFMQTT.PubEventHandler
XFMQTT.SubedEventHandler
XFMQTT.UnSubedEventHandler
委托 | 说明 |
XFMQTT.PubEventHandler | 订阅回调 - 当收到服务器消息时 |
XFMQTT.PubedEventHandler | 当 QOS=1或2时,收到订阅触发 |
XFMQTT.SubedEventHandler | 向服务器发布 Topic 时 |
XFMQTT.SubedEventHandler | 向服务器发布 Topic 失败时 |
XFMQTT.ConnectionClosedEventHandler | 断开连接 |
MQTT是一种可靠的消息推送协议,QOS保证了消息必须完整地推送给另一端,关于QOS具体可以百度~
- QOS = 0 ,最多一次
- QOS = 1,至少一次
- QOS = 2,只有一次
代表消息推送地可靠程度,当 QOS = 1是,在网络波动等情况下,可能会存在多次重复的一次推送。
使用默认的委托方法:
// 使用默认的委托事件 client.UseDefaultEventHandler();
通过上一篇文章,程序已经可以运行、连接到阿里云服务器,并且可以订阅发布消息。
这些操作都会触发事件,通过 UseDefaultEventHandler() 方法,使用的默认的方法绑定到事件。
自定义事件方法
删除 这一行代码
client.UseDefaultEventHandler();
头部引入
using uPLibrary.Networking.M2Mqtt.Messages;
注意,这五个委托方法的参数是不一样的。
XFMQTT.PubEventHandler
订阅回调 - 当收到服务器消息时触发
委托方法如下
委托方法(object sender, MqttMsgPublishEventArgs e) { }
MqttMsgPublishEventArgs 是与接收消息有关的对象,其属性如下:
// 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 默认的委托方法
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); }
那么我们来写一个自定义委托方法
里面的怎么写都行,方法名称随意
public static void 收到消息(object sender, MqttMsgPublishEventArgs e) { Console.WriteLine("topic名称:"+e.Topic); Console.WriteLine("接收时间:" + DateTime.Now.ToLongDateString()); Console.WriteLine("消息内容:\n"+Encoding.ASCII.GetString(e.Message)); }
在删除 client.UseDefaultEventHandler(); 的位置加上
client.PubEventHandler += 收到消息;
XFMQTT.PubedEventHandler
当 QOS=1或2时,收到订阅触发
原型
委托方法(object sender, MqttMsgPublishedEventArgs e) { }
MqttMsgPublishedEventArgs 属性
// message identifier ushort messageId; // published flag bool isPublished;
SDK 默认方法
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); }
我们来自定义写,方法名称随意
public static void 重复收到消息(object sender, MqttMsgPublishedEventArgs e) { Console.WriteLine("接收时间: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("消息id: " + e.MessageId + " Is Published: " + e.IsPublished); }
加上
client.PubedEventHandler += 重复收到消息;
XFMQTT.SubedEventHandler
向服务器发布 Topic 时触发
原型
void 发布消息时(object sender, MqttMsgSubscribedEventArgs e)
MqttMsgSubscribedEventArgs 属性
/// <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 默认写法
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)); }
我们来自定义写,方法名称随意
public static void 发布消息时(object sender, MqttMsgSubscribedEventArgs e) { Console.WriteLine("向服务器发送了消息"); Console.WriteLine("发送时间: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("消息id: " + e.MessageId); Console.WriteLine("QOS 为 : " + Encoding.UTF8.GetString(e.GrantedQoSLevels)); }
加上
client.SubedEventHandler += 发布消息时;
XFMQTT.UnSubedEventHandler
向服务器发布 Topic 失败时触发
void 发送失败(object sender, MqttMsgUnsubscribedEventArgs ) { }
MqttMsgUnsubscribedEventArgs 属性
/// <summary> /// Message identifier /// </summary> public ushort MessageId { get { return this.messageId; } internal set { this.messageId = value; } }
SDK 写法
public void Default_UnSubedEventHandler(object sender, MqttMsgUnsubscribedEventArgs e) { Console.WriteLine("- - - - - - - - - - "); Console.WriteLine("Sub topic error,Date: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("MessageId: " + e.MessageId); }
我们自定义写
public static void 发送失败(object sender, MqttMsgUnsubscribedEventArgs e) { Console.WriteLine("消息发送失败 "); Console.WriteLine("时间: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("失败的消息 MessageId: " + e.MessageId); }
加上
client.UnSubedEventHandler += 发送失败;
XFMQTT.ConnectionClosedEventHandler
断开连接时触发
SDK 写法
public void Default_ConnectionClosedEventHandler(object sender, EventArgs e) { Console.WriteLine("- - - - - - - - - - "); Console.WriteLine("Connect Closed error,Date: " + DateTime.Now.ToLongTimeString()); }
自定义写
public static void 断开连接(object sender, EventArgs e) { Console.WriteLine("日。。。连接断开了: " + DateTime.Now.ToLongTimeString()); }
加上
client.ConnectionClosedEventHandler += 断开连接;
完整代码
static void Main(string[] args) { // 创建连接对象 XFMQTT client = new XFMQTT("a1BiPoNawLI", "Raspberry"); // 初始化客户端配置 client.Init("2NOaBeqXcIzLQEhlJFEfKbWeug0o3m0c", "cn-shanghai"); // 要订阅的Topic string[] topic = { client.CombineHeadTopic("PubData") }; // 使用自定义的委托事件 client.PubEventHandler += 收到消息; client.PubedEventHandler += 重复收到消息; client.SubedEventHandler += 发布消息时; client.UnSubedEventHandler += 发送失败; client.ConnectionClosedEventHandler += 断开连接; // 连接服务器 client.ConnectMqtt(topic); while (true) { string str = Console.ReadLine(); // 推送内容到特定的 Topic client.Subscribe(client.CombineHeadTopic("SubData"), str); } Console.ReadKey(); } public static void 收到消息(object sender, MqttMsgPublishEventArgs e) { Console.WriteLine("topic名称:"+e.Topic); Console.WriteLine("接收时间:" + DateTime.Now.ToLongDateString()); Console.WriteLine("消息内容:\n"+Encoding.ASCII.GetString(e.Message)); } public static void 重复收到消息(object sender, MqttMsgPublishedEventArgs e) { Console.WriteLine("接收时间: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("消息id: " + e.MessageId + " Is Published: " + e.IsPublished); } public static void 发布消息时(object sender, MqttMsgSubscribedEventArgs e) { Console.WriteLine("向服务器发送了消息"); Console.WriteLine("发送时间: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("消息id: " + e.MessageId); Console.WriteLine("QOS 为 : " + Encoding.UTF8.GetString(e.GrantedQoSLevels)); } public static void 发送失败(object sender, MqttMsgUnsubscribedEventArgs e) { Console.WriteLine("消息发送失败 "); Console.WriteLine("时间: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("失败的消息 MessageId: " + e.MessageId); } public static void 断开连接(object sender, EventArgs e) { Console.WriteLine("日。。。连接断开了: " + DateTime.Now.ToLongTimeString()); }
但是这样子不好,换种写法
class Program { static void Main(string[] args) { // 创建连接对象 XFMQTT client = new XFMQTT("a1BiPoNawLI", "Raspberry"); // 初始化客户端配置 client.Init("2NOaBeqXcIzLQEhlJFEfKbWeug0o3m0c", "cn-shanghai"); // 要订阅的Topic string[] topic = { client.CombineHeadTopic("PubData") }; // 使用自定义的委托事件 事件类 事件 = new 事件类(); client.PubEventHandler += 事件.收到消息; client.PubedEventHandler += 事件.重复收到消息; client.SubedEventHandler += 事件.发布消息时; client.UnSubedEventHandler += 事件.发送失败; client.ConnectionClosedEventHandler += 事件.断开连接; // 连接服务器 client.ConnectMqtt(topic); while (true) { string str = Console.ReadLine(); // 推送内容到特定的 Topic client.Subscribe(client.CombineHeadTopic("SubData"), str); } Console.ReadKey(); } } public class 事件类 { public void 收到消息(object sender, MqttMsgPublishEventArgs e) { Console.WriteLine("topic名称:" + e.Topic); Console.WriteLine("接收时间:" + DateTime.Now.ToLongDateString()); Console.WriteLine("消息内容:\n" + Encoding.ASCII.GetString(e.Message)); } public void 重复收到消息(object sender, MqttMsgPublishedEventArgs e) { Console.WriteLine("接收时间: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("消息id: " + e.MessageId + " Is Published: " + e.IsPublished); } public void 发布消息时(object sender, MqttMsgSubscribedEventArgs e) { Console.WriteLine("向服务器发送了消息"); Console.WriteLine("发送时间: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("消息id: " + e.MessageId); Console.WriteLine("QOS 为 : " + Encoding.UTF8.GetString(e.GrantedQoSLevels)); } public void 发送失败(object sender, MqttMsgUnsubscribedEventArgs e) { Console.WriteLine("消息发送失败 "); Console.WriteLine("时间: " + DateTime.Now.ToLongTimeString()); Console.WriteLine("失败的消息 MessageId: " + e.MessageId); } public void 断开连接(object sender, EventArgs e) { Console.WriteLine("日。。。连接断开了: " + DateTime.Now.ToLongTimeString()); } }
使用默认事件方法与自定义事件方法并不冲突。
// 使用默认事件方法 client.UseDefaultEventHandler(); // 使用自定义的委托事件 事件类 事件 = new 事件类(); client.PubEventHandler += 事件.收到消息; client.PubedEventHandler += 事件.重复收到消息; client.SubedEventHandler += 事件.发布消息时; client.UnSubedEventHandler += 事件.发送失败; client.ConnectionClosedEventHandler += 事件.断开连接;
为便于理解,上面事件方法使用了中文名称,请根据实际修改。