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在使用我编写的 TCP 服务器接收数据时，我遇到了随机出现神秘错误的问题。例外情况如下：

System.Net.Sockets.SocketException (0x80004005): An established connection was aborted by the software in your host machine
   at System.Net.Sockets.Socket.BeginReceive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags, AsyncCallback callback, Object state)
   at TTS_Simulator.TCPChannel.ReceiveData(IAsyncResult ar)

我正在使用 BeginXXX 和 EndXXX 异步方法，对方肯定没有关闭连接。

负责接受连接的代码：

    protected void AcceptCallback(IAsyncResult ar)
    {
        try
        {
            Socket listener = (Socket)ar.AsyncState;
            Socket handler = listener.EndAccept(ar);
            _logger.Info("Connection request accepted on local endpoint: " + listener.LocalEndPoint);
            _logger.Info("Connection request accepted from remote endpoint: " + handler.RemoteEndPoint);
            Thread.Sleep(100);

            StateObject state = new StateObject { workSocket = handler };
            handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                ReceiveData, state);
            IsConnected = true;
            ControlActivator?.Invoke(true);
            listener.BeginAccept(AcceptCallback, listener);
        }
        catch (SocketException ex)
        {
            _logger.Error(ex);
        }
        catch (NullReferenceException ex)
        {
            _logger.Error(ex);
        }
    }

以及负责接收消息的代码：

    protected void ReceiveData(IAsyncResult ar)
    {
        StateObject state = (StateObject)ar.AsyncState;
        Socket handler = state.workSocket;
        string _inputData = String.Empty;
        int totalBytesRead = 0;
        int bytesRead = 0;

        try
        {
            bytesRead = handler.EndReceive(ar);
            totalBytesRead += bytesRead;

            if (totalBytesRead == 0)
            {
                _logger.Info("Client disconnected at: " + handler.LocalEndPoint);
                handler.Disconnect(true);
                handler.Close();
                handler.Dispose();
                IsConnected = false;
                ControlActivator?.Invoke(false);
                return;
            }

            if (totalBytesRead > 0)
            {
                if (handler.Available > 0)
                {
                    bytesRead = handler.Receive(state.buffer, bytesRead, StateObject.BufferSize,
                        SocketFlags.None);
                    totalBytesRead += bytesRead;
                }
            }
            DataHandler(handler, state.buffer, totalBytesRead);
            totalBytesRead = 0;
            state.workSocket.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, ReceiveData, state);
        }
        catch (System.Net.Sockets.SocketException ex)
        {
            _logger.Error("Error receiving data! \n" + ex);
        }
        catch (Exception ex)
        {
            _logger.Error("Error when processing the data! \n" + ex);
        }
    }

有时，服务器和客户端都报告完全相同的问题，有时，它只是服务器或客户端。同样有趣的是，当服务器接受连接时，我可以在日志中看到实际上有两个连接请求，都被接受了。不知道这是否与它有关......只是一个侧面说明，服务器和客户端都在同一台机器上运行，这是一个 MS Azure VM。如果需要，我还可以附上服务器的整个代码。

谢谢！

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