Socket temp=new Socket (AddressFamily .InterNetwork ,SocketType.Dgram ,ProtocolType.Udp );
            IPAddress [] localIP=Dns.GetHostAddresses (Dns.GetHostName ());
            string localHost = Environment.UserName;
            string InitialInformation = "JOIN" + "/" + localIP[0].ToString() + "/" + "5000" + "/" + localHost;
            Byte[] buffer = Encoding.Unicode.GetBytes(InitialInformation);
            //IPAddress .Broadcast为有限广播地址255.255.255.255
            IPEndPoint remotEndPoint=new IPEndPoint (IPAddress .Broadcast,5000);
            temp.SendTo (buffer ,remotEndPoint );//异常处....
异常提示:
未处理 System.Net.Sockets.SocketException
  Message="以一种访问权限不允许的方式做了一个访问套接字的尝试。"
  Source="System"
  ErrorCode=10013
  NativeErrorCode=10013
  StackTrace:
       在 System.Net.Sockets.Socket.SendTo(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags, EndPoint remoteEP)
       在 System.Net.Sockets.Socket.SendTo(Byte[] buffer, EndPoint remoteEP)
    请达人指点,在此先谢谢了!