用udp写个服务器怎么获取客户端的ipep？

[bluesands_zhang]

看了msdn中的代码，客户端的ip是人为指定的，而不能处理多个客户端的接入
是不是服务器客户端的程序服务器端只能用tcp连接，而不能用udp的无连接协议？
udp作为无连接的只能用于点对点的通信？

public static bool messageReceived = false;

public static void ReceiveCallback(IAsyncResult ar)
{
  UdpClient u = (UdpClient)((UdpState)(ar.AsyncState)).u;
  IPEndPoint e = (IPEndPoint)((UdpState)(ar.AsyncState)).e;

  Byte[] receiveBytes = u.EndReceive(ar, ref e);
  string receiveString = Encoding.ASCII.GetString(receiveBytes);

  Console.WriteLine("Received: {0}", receiveString);
  messageReceived = true;
}

public static void ReceiveMessages()
{
  // Receive a message and write it to the console.
  IPEndPoint e = new IPEndPoint(IPAddress.Any, listenPort);
  UdpClient u = new UdpClient(e);

  UdpState s = new UdpState();
  s.e = e;
  s.u = u;

  Console.WriteLine("listening for messages");
  u.BeginReceive(new AsyncCallback(ReceiveCallback), s);

  // Do some work while we wait for a message. For this example,
  // we'll just sleep
  while (!messageReceived)
  {
    Thread.Sleep(100);
  }
}

[gxingmin]

internal void OnDataReceived(IAsyncResult ar) { try { Socket udpSocket = ar.AsyncState as Socket; int bytesRecved = udpSocket.EndReceiveFrom(ar, ref remoteEP); string ip=remoteEP.split(':')[0]; //对方ip string port=remoteEP.split(':')[1];//对方端口 ...