C#UDP通信

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;

namespace LcSoftCard.Service
{
    public class UDPConsumeServiceDS
    {
        private bool flag;
        public bool Flag
        {
            get { return flag; }
            set { flag = value; }
        }

        private IPEndPoint SendPoint;
        private const int ConsumeRecCmdBackPort = 9998;   //接收命令返回端口--第一路遠程主從端口：9998  --PC
        // --第一路本地主從端口：10000  --消費機 接收命令返回端口
        private int ConsumeRecDataPort = Convert.ToInt32(ConfigurationManager.ConnectionStrings["FirstLocalPost"].ConnectionString.ToString());   //接收命令返回端口

        private UdpClient UdpRecCmdBack;         //接收發送命令返回數據
        private Thread ThreadRecCmdBack;
        private IPEndPoint RecCmdBackPiont;

        public delegate void ConsumeHandler(string msg);        //聲明委托
        public event ConsumeHandler ConsumeEvent;           //聲明事件

        public void SendCommand(string cmd, string ip)
        {
            string rst = cmd.ToUpper() + AscSum(cmd.ToUpper());
            SendPoint = new IPEndPoint(IPAddress.Parse(ip), ConsumeRecDataPort);
            byte[] SendData = Encoding.ASCII.GetBytes(rst);
            uint IOC_IN = 0x80000000;
            uint IOC_VENDOR = 0x18000000;
            uint SIO_UDP_CONNRESET = IOC_IN | IOC_VENDOR | 12;
            UdpRecCmdBack.Client.IOControl((int)SIO_UDP_CONNRESET, new byte[] { Convert.ToByte(false) }, null);
            UdpRecCmdBack.Send(SendData, SendData.Length, SendPoint);
        }

        /// <summary>
        /// ASCII求和
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public string AscSum(string str)
        {
            int sum = 0;
            string rst;
            if (str.Length == 0) return "00";
            System.Text.ASCIIEncoding asciiEncoding = new System.Text.ASCIIEncoding();
            for (int i = 0; i < str.Length; i++)
            {
                sum += (int)asciiEncoding.GetBytes(str)[i];
            }
            sum %= 0x100;
            rst = sum.ToString("x");
            if (rst.Length < 2) rst = "0" + rst;
            return rst.ToUpper();
        }

        public void StartRecCmdBackListen()
        {
            while (true)
            {
                byte[] recData = UdpRecCmdBack.Receive(ref RecCmdBackPiont);
                string ReadStr = BitConverter.ToString(recData).Replace("-", "");
                ReadStr = Encoding.ASCII.GetString(recData);
                Flag = true;
                if (ConsumeEvent != null)
                {
                    ConsumeEvent(ReadStr);
                }
            }
        }

        /// <summary>
        /// 開啟監聽線程
        /// </summary>
        public void ConsumeRun()
        {
            UdpRecCmdBack = new UdpClient(ConsumeRecCmdBackPort);
            ThreadRecCmdBack = new Thread(new ThreadStart(StartRecCmdBackListen));
            ThreadRecCmdBack.IsBackground = true;
            ThreadRecCmdBack.Start();
        }

        public void ConsumeStop()
        {
            if (ThreadRecCmdBack != null)
            {
                ThreadRecCmdBack.Abort();
                UdpRecCmdBack.Close();
            }
        }
    }
}