CZGL.AliIoTClient 有7个委托事件，设置了默认的方法。
你可以通过下面的方法使用默认的方法绑定到委托事件中。

public void UseDefaultEventHandler()

1）默认的方法

收到服务器下发属性设置时：

public void Default_PubPropertyEventHandler(object sender, 
                                            MqttMsgPublishEventArgs e)

收到服务器调用服务命令时：

public void Default_PubServiceEventHandler(object sender, 
                                           MqttMsgPublishEventArgs e)

收到普通Topic、上传数据的响应等其它情况：

public void Default_PubCommonEventHandler(object sender, 
                                          MqttMsgPublishEventArgs e)

收到服务器QOS为1的推送

public void Default_PubedEventHandler(object sender, 
                                      MqttMsgPublishedEventArgs e)

当向服务器发送消息成功时：

public void Default_SubedEventHandler(object sender, 
                                      MqttMsgSubscribedEventArgs e)

向服务器推送消息失败时：

public void Default_UnSubedEventHandler(object sender, 
                                        MqttMsgUnsubscribedEventArgs e)

连接断开时

public void Default_ConnectionClosedEventHandler(object sender, 
                                                 System.EventArgs e)

2）方法的写法

不同的委托参数不同，有好几种类型，参考笔者的方法使用参数。

     /// 一般的推送
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        public void Default_PubCommonEventHandler(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);
        }
        /// <summary>
        /// 收到属性设置
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        public void Default_PubPropertyEventHandler(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);
        }
        /// <summary>
        /// 收到服务调用
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        public void Default_PubServiceEventHandler(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);
        }
        /// <summary>
        /// 收到服务器QOS为1的推送
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        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);
        }
        /// <summary>
        /// 向服务器推送成功
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        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));
        }
        /// <summary>
        /// 推送失败
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        public void Default_UnSubedEventHandler(object sender, MqttMsgUnsubscribedEventArgs e)
        {
            Console.WriteLine("- - - - - - - - - - ");
            Console.WriteLine("Sub topic error,Date: " + DateTime.Now.ToLongTimeString());
            Console.WriteLine("MessageId:    " + e.MessageId);
        }
        /// <summary>
        /// 连接发生异常，断网等
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        public void Default_ConnectionClosedEventHandler(object sender, EventArgs e)
        {
            Console.WriteLine("- - - - - - - - - - ");
            Console.WriteLine("Connect Closed error,Date: " + DateTime.Now.ToLongTimeString());
        }