一个事件委托的问题？

Question

各位

//class 1
namespace Link
{
    public class AsynSocketListener
    {
        private static AsynSocketListener _asynl = null;
        public static AsynSocketListener Instance
        {
            get
            {
                if (_asynl == null)
                {
                    _asynl = new AsynSocketListener();
                }
                return _asynl;
            }
        }

        /// <summary>
        /// 构造
        /// </summary>
        public AsynSocketListener()
        {
            //check alive
            keepalivetimer = new Timer(this.CheckAlive, null, 500, 500);

        }
        /// <summary>
        /// 监控客户端udp信息
        /// </summary>
        /// <returns></returns>
        public void UDP_Monitor()
        {
            sock = new Socket(AddressFamily.InterNetwork,
            SocketType.Dgram, ProtocolType.Udp);
            IPEndPoint iep = new IPEndPoint(IPAddress.Any, 9050);
            sock.Bind(iep);
            ep = (EndPoint)iep;
            sock.BeginReceiveFrom(returnmsgs, 0, returnmsgs.Length, SocketFlags.None, ref ep, new AsyncCallback(BeginRecieved), sock);
        }

 private void BeginRecieved(IAsyncResult ar)
        {
            Socket client = (Socket)ar.AsyncState;
            ResultEventArgs e = new ResultEventArgs();
            try
            {
                //receive byte[]
                int n = client.EndReceive(ar);
                returnmsgstomsgs(n);
                if (nb > 0)
                {
                    e.Socket = client;
                    e.ReceiveByte = msgs;
                    e.RecievedCommandDateTime = DateTime.Now;
                    string userId = Encoding.ASCII.GetString(e.ReceiveByte, 3, 6);
                    if (msgs[0].ToString() == "57" && msgs[1].ToString() == "51" && msgs[nb - 1].ToString() == "52")
                    {
                        switch (msgs[2])
                        {
                            case 49:
                                KeepAliveCheck kp = new KeepAliveCheck(userId.ToString());
                                this.OnTerminalResultCompleted(this, e);
                                break;
                       }
                        msgs = null;
                        nb = 0;
                    }
                }
                //继续非同步呼叫Receive
                client.BeginReceive(returnmsgs, 0, returnmsgs.Length, SocketFlags.None, new AsyncCallback(BeginRecieved), client);
            }
            catch
            {
                // throw;
                msgs = null;
                nb = 0;

                client.BeginReceive(returnmsgs, 0, returnmsgs.Length, SocketFlags.None, new AsyncCallback(BeginRecieved), client);
            }
        }

        /// <summary>
        /// 机器回应事件
        /// </summary>
        public event EventHandler TerminalResulted;

        #region 机器回应触发事件
        private void OnTerminalResultCompleted(object sender, ResultEventArgs e)
        {
            if (this.TerminalResulted != null)
            {
                this.TerminalResulted(this, e);
            }
        }
        #endregion

    }
}




//class 2

namespace Link.Command
{
    public class KeepAliveCheck : BaseSemacCommand
    {
        public KeepAliveCheck(string userId)
        {
            this.userId = userId;
            this.Command = 49;
        }

        /// <summary>
        /// 机器回应后触发的事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected override void Instance_TerminalResulted(object sender, EventArgs e)
        {
            ResultEventArgs re = (ResultEventArgs)e;
            string userId = Encoding.ASCII.GetString(re.ReceiveByte, 3, 6);
            if (AsynSocketListener.Instance.SocketIsIn(userId.ToString()))
            {
                AsynSocketListener.Instance.SocketUpdateKeepAliveTime(re.Socket, re.ReceiveByte);
            }
            else
            {
                SocketObject so = new SocketObject(re.Socket, userId.ToString(), re.ReceiveByte);
                AsynSocketListener.Instance.SocketList.Add(so);
            }
        }

        public override byte[] CreateCommand()
        {
            byte[] r = new byte[11];
            return r;
        }
        public override byte[] CreateCommand(string[] a)
        {
            byte[] r = new byte[11];
            return r;
        }
    }
}



//class 3

namespace Link.Command
{
    /// <summary>
    /// 基类
    /// </summary>
    public abstract class BaseSemacCommand
    {

        #region 属性
        /// <summary>
        /// 指令送出的时间
        /// </summary>
        public DateTime SendCommandDateTime { set; get; }
        public string Key { get; set; }
        /// <summary>
        /// 16進位 Command
        /// </summary>
        protected byte Command = 0x00;

        /// <summary>
        /// 用户编号
        /// </summary>
        public string userId { set; get; }

        #endregion

        public abstract byte[] CreateCommand();
        public abstract byte[] CreateCommand(string[] data);


        public BaseSemacCommand()
        {
            this.SendCommandDateTime = DateTime.Now;
            this.Key = Guid.NewGuid().ToString();

            //声明事件
            AsynSocketListener.Instance.TerminalResulted += new EventHandler(Instance_TerminalResulted);
         }

        protected virtual void Instance_TerminalResulted(object sender, EventArgs e) { }


    }
}

先看代码

在class 1 AsynSocketListener中是udp接受数据，在接收到数据有实例class 2 KeepAliveCheck 类 KeepAliveCheck 是继承与class3 BaseSemacCommand类，问题是在BaseSemacCommand中 AsynSocketListener.Instance.TerminalResulted += new EventHandler(Instance_TerminalResulted)添加了事件委托方法，现在问题是在KeepAliveCheck 类中运行到   private void OnTerminalResultCompleted(object sender, ResultEventArgs e)方法时 if (this.TerminalResulted != null)总是=null。有谁知道愿意的。希望大家帮帮我。小弟先谢了。

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pinkbull

Answer 1

Hi frank-gao,

当前论坛仅对C#语言为主的问题进行支持，涉及到Socket编程的问题请你到.NET Framework 一般性问题讨论区去发帖询问。
谢谢你的理解。

祝你快乐每一天，

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Leo Liu [MSFT]
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