c# mobile5.0 socket同步客户端无法连接异步服务端

服务端
          IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
            IPAddress ipAddress = ipHostInfo.AddressList[0];
            IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 7074);            listener = new Socket(AddressFamily.InterNetwork,
                SocketType.Stream, ProtocolType.Tcp);
            try
            {
                listener.Bind(localEndPoint);
                listener.Listen(100);                while (true)
                {                    allDone.Reset();
                    listener.BeginAccept(
                        new AsyncCallback(AcceptCallback),
                        listener);
                    allDone.WaitOne();客户端（客户端同步异步都无法连接服务端，除非服务端用同步监听就可以。这是为什么呢）
     hostIPAddress = IPAddress.Parse("130.120.2.157");
            int port = 7073;
            Server = new IPEndPoint(hostIPAddress, port);
         //   _socket.BeginConnect(Server, new AsyncCallback(ConnectCallBack), _socket);
           _socket.Connect(Server);
            //开启接收信息线程
            if (_socket.Connected)
            {
                 
            }