win8 metro socket

private async void btnListen_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                _listener = new StreamSocketListener();

                //_listener.Control.QualityOfService = SocketQualityOfService.Normal;

                _listener.ConnectionReceived += _listener_ConnectionReceived;
                await _listener.BindEndpointAsync(_localHostName, _localServerName);
                btnListen.IsEnabled = false;
                btnStopListen.IsEnabled = true;
            }
            catch (Exception ex)
            {
                var status = SocketError.GetStatus(ex.HResult);
            }
        }

        private DataReader reader;

        /// <summary>
        /// 处理接入的请求
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="args"></param>
        void _listener_ConnectionReceived(StreamSocketListener sender, StreamSocketListenerConnectionReceivedEventArgs args)
        {
            reader = new DataReader(args.Socket.InputStream);
            ReceiveStringLoop(reader, args.Socket);
            //ReceiveDataLoop(_reader,args.Socket);
        }

        /// <summary>
        /// 循环处理数据
        /// </summary>
        /// <param name="reader"></param>
        /// <param name="socket"></param>
        private void ReceiveStringLoop(DataReader reader, StreamSocket socket)
        {
            try
            {
                reader.LoadAsync(sizeof(uint)).AsTask().ContinueWith((result) =>
                  {
                      uint size = (uint)result.Result;

                      if (size < sizeof(uint))
                      {
                          // The underlying socket was closed before we were able to read the whole data.
                          return;
                      }

                      uint stringLength = reader.ReadUInt32();
                      reader.LoadAsync((uint)stringLength).AsTask().ContinueWith((strLength) =>
                      {
                          string msg = reader.ReadString(reader.UnconsumedBufferLength);
                          ShowMessage(msg);
                      });
                  }).ContinueWith((e) =>
                  {
                      //这里注意要新new一个DataReader对象
                      ReceiveStringLoop(new DataReader(socket.InputStream), socket);
                  });
            }
            catch (Exception ex)
            {
                SocketErrorStatus status = SocketError.GetStatus(ex.HResult);
            }
        }

        private async void ReceiveDataLoop(DataReader reader, StreamSocket streamSocket)
        {
            try
            {
                await _reader.LoadAsync(sizeof(uint));
                uint size = _reader.ReadUInt32();
                await _reader.LoadAsync(size);
                //byte[] data = new byte[size];
                //reader.ReadBytes(data);
                string msg = _reader.ReadString(reader.UnconsumedBufferLength);
                ShowMessage(msg);
                ReceiveDataLoop(_reader, streamSocket);
            }
            catch (Exception ex)
            {
            
            }
        }

        private void btnStopListen_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                _listener.Dispose();
                // reader.Dispose();
                btnListen.IsEnabled = true;
                btnStopListen.IsEnabled = false;
            }
            catch (Exception ex)
            {
                var status = SocketError.GetStatus(ex.HResult);
            }
        }

        /// <summary>
        /// 开始连接服务器
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void btnConnect_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                _client = new StreamSocket();

                _client.Control.KeepAlive = true;
                _client.Control.NoDelay = true;
                _client.Control.QualityOfService = SocketQualityOfService.Normal;

                await _client.ConnectAsync(_localHostName, _localServerName);

                btnConnect.IsEnabled =false;
                btnDisconnect.IsEnabled = true;
            }
            catch (Exception ex)
            {
                SocketErrorStatus status = SocketError.GetStatus(ex.HResult);
            }
        }

        /// <summary>
        /// 开始发送
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void btnSend_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                string sendMsg = tbInputMsg.Text.Trim();
                int strLength = sendMsg.Length;

                DataWriter writer = new DataWriter(_client.OutputStream);

                //注意一定要先发送要发送数据的长度
                writer.WriteInt32(strLength);
                writer.WriteString(sendMsg);
                await writer.StoreAsync();

                await _client.OutputStream.FlushAsync();

                tbSendMsg.Text += ("Send-->: " + tbInputMsg.Text + Environment.NewLine);
                tbInputMsg.Text = string.Empty;
                ////await _client.OutputStream.WriteAsync(GetBufferFromString(strLength.ToString()));
                //await _client.OutputStream.WriteAsync(GetBufferFromString(tbInputMsg.Text.Trim()));
                //await _client.OutputStream.FlushAsync();
            }
            catch (Exception ex)
            {
                SocketErrorStatus status = SocketError.GetStatus(ex.HResult);
            }
        }

        /// <summary>
        /// 断开连接
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnDisconnect_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                _client.Dispose();

                btnConnect.IsEnabled = true;
                btnDisconnect.IsEnabled = false;
            }
            catch (Exception ex)
            {
                SocketErrorStatus status = SocketError.GetStatus(ex.HResult);
            }
        }