C# UDP 连接通信 简单示例

Udp.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;

namespace udp
{
    public delegate void UdpEventHandler(object sender, UdpEventArgs e);

    public abstract class Udp : IUdp
    {
        public event UdpEventHandler Received;

        private int _port;
        private string _ip;
        public bool IsListening { get; private set; }
        private Socket _sck;

        public Socket UdpSocket
        {
            get { return _sck; }
        }
        public string Ip
        {
            get { return _ip; }
            set { _ip = value; }
        }
        public int Port
        {
            get { return _port; }
            set
            {
                if (value < 0)
                    value = 0;
                if (value > 65536)
                    value = 65536;
                _port = value;
            }
        }

        public Udp()
        {
            _sck = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            _sck.ReceiveBufferSize = UInt16.MaxValue * 8;
            //log
            System.Diagnostics.Trace.Listeners.Clear();
            System.Diagnostics.Trace.AutoFlush = true;
            System.Diagnostics.Trace.Listeners.Add(new System.Diagnostics.TextWriterTraceListener("log.txt"));
        }


        public void Listening()
        {
            IPAddress ip = IPAddress.Any;
            try
            {
                if (this._ip != null)
                    if (!IPAddress.TryParse(this._ip, out ip))
                        throw new ArgumentException("IP地址错误", "Ip");
                _sck.Bind(new IPEndPoint(ip, this._port));

                UdpState state = new UdpState();
                state.Socket = _sck;
                state.Remote = new IPEndPoint(IPAddress.Any, 0);
                _sck.BeginReceiveFrom(state.Buffer, 0, state.Buffer.Length, SocketFlags.None, ref state.Remote, new AsyncCallback(EndReceiveFrom), state);
                IsListening = true;
            }
            catch (ArgumentException ex)
            {
                IsListening = false;
                System.Diagnostics.Trace.WriteLine(DateTime.Now.ToString() + "\t" + ex.Message);
                throw ex;
            }
            catch (Exception ex)
            {
                IsListening = false;
                System.Diagnostics.Trace.WriteLine(DateTime.Now.ToString() + "\t" + ex.Message);
                throw ex;
            }
        }
        private void EndReceiveFrom(IAsyncResult ir)
        {
            if (IsListening)
            {
                UdpState state = ir.AsyncState as UdpState;
                try
                {
                    if (ir.IsCompleted)
                    {
                        int length = state.Socket.EndReceiveFrom(ir, ref state.Remote);
                        byte[] btReceived = new byte[length];
                        Buffer.BlockCopy(state.Buffer, 0, btReceived, 0, length);
                        OnReceived(new UdpEventArgs(btReceived, state.Remote));
                    }
                }
                catch (Exception ex)
                {
                    System.Diagnostics.Trace.WriteLine(DateTime.Now.ToString() + "\t" + ex.Message+ex.Source);
                }
                finally
                {
                    state.Socket.BeginReceiveFrom(state.Buffer, 0, state.Buffer.Length, SocketFlags.None, ref state.Remote, new AsyncCallback(EndReceiveFrom), state);
                }
            }
        }

        private void OnReceived(UdpEventArgs e)
        {
            if (this.Received != null)
            {
                Received(this, e);
            }
        }

        public void Send(byte[] bt, EndPoint ep)
        {
            if (_sck == null) return;
            try
            {
                this._sck.SendTo(bt, ep);
            }
            catch (SocketException ex)
            {
                System.Diagnostics.Trace.WriteLine(DateTime.Now.ToString() + "\t" + ex.Message);
                throw ex;
            }
        }

        public void Dispose()
        {
            if (_sck == null) return;

              using (_sck) ;
            //this.IsListening = false;
            //this._sck.Blocking = false;
            //this._sck.Shutdown(SocketShutdown.Both);
            //this._sck.Close();
            //this._sck = null;
        }

    }
}

IUdp.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;
using System.Net;

namespace udp
{
    public interface IUdp : IDisposable
    {
        event UdpEventHandler Received;

        void Send(byte[] bt, EndPoint ep);

        Socket UdpSocket { get; }
    }
}

UdpEventArgs.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;

namespace udp
{
    public class UdpEventArgs : EventArgs
    {
        private EndPoint _remote;

        private byte[] _rec;

        public byte[] Received
        {
            get { return _rec; }
        }
        public EndPoint Remote
        {
            get { return _remote; }
        }

        public UdpEventArgs(byte[] data, EndPoint remote)
        {
            this._remote = remote;
            this._rec = data;
        }
    }
}

UdpState.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;

namespace udp
{
    internal class UdpState
    {
        public byte[] Buffer;
        public EndPoint Remote;
        public Socket Socket;

        public UdpState()
        {
            Buffer = new byte[65536];
        }
    }
}

Client

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;
using System.Net;
using udp;
namespace client
{
    class Program
    { 
        private const string _serverIp = "127.0.0.1";
        private const int _serverPort = 8000;

        static void Main(string[] args)
        {
            Client client = new Client();
            client.ep = new IPEndPoint(IPAddress.Parse(_serverIp), _serverPort);
            client.Listening();
            client.Received += new UdpEventHandler(client_Received);
            while (true)
            {
                string tmp = Console.ReadLine();
                for (int i = 0; i < 10; i++)
                {
                    byte[] bt = Encoding.Default.GetBytes(tmp + i);
                    System.Threading.Thread t = new System.Threading.Thread(() =>
                    {
                        client.Send(bt, client.ep);
                    });
                    t.Start();
                }
                client.Dispose();
            }
        }

        static void client_Received(object sender, UdpEventArgs e)
        {
            IPEndPoint ep = e.Remote as IPEndPoint;
            string tmpReceived = Encoding.Default.GetString(e.Received);
            Console.WriteLine(ep.Address.ToString() + ":" + ep.Port + "--> " + tmpReceived);
        }
    }

    public class Client : Udp
    {
        public EndPoint ep;
        public Client()
        {

        }
    }
}

Server

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Net.Sockets;
using System.Net;
using udp;

namespace server
{
    class Program
    { 
        static Server server = new Server();
        static void Main(string[] args)
        {
            server.Port = 8000;
            server.Listening();
            if (server.IsListening)
            {
                server.Received += new UdpEventHandler(server_Received);
            }
            Console.ReadKey();
        }

        static void server_Received(object sender, UdpEventArgs e)
        {
            IPEndPoint ep = e.Remote as IPEndPoint;
            string tmpReceived = Encoding.Default.GetString(e.Received);
            Console.WriteLine(ep.Address.ToString() + ":" + ep.Port + "--> " + tmpReceived);
            ///自动回复
            server.Send(Encoding.Default.GetBytes("服务器已收到数据:'" + tmpReceived + "',来自:‘" + ep.Address.ToString() + ":" + ep.Port + "’"), ep);
        }

    }
    public class Server : Udp
    {
        private EndPoint ep;
        public Server()
        {
        }
    }
}

源码文件