TCP 套接字客户端\服务器请求响应

Question

我正在开发一个 .Net 4.5.2 windows TCP 套接字主\客户端消息解决方案。该解决方案在很大程度上是有效的； however I need the server to send a response message back to the client when the send button is selected.选择“连接”按钮时，Master确实成功地将响应消息发送回客户端。 I have made numerous attempts to send the response message back to the client application from the master when the send button is selected, but I have been unable to make it work.我正在寻求一些帮助，让我再次前进。不想继续转动我的轮子而没有进展。在此先感谢您的帮助。请在下面找到服务器和客户端解决方案：

服务器代码：

 public partial class ServerForm : Form
    {
        private Socket serverSocket;
        private Socket clientSocket; // We will only accept one socket.
        private byte[] buffer;

        public ServerForm()
        {
            InitializeComponent();
            StartServer();
        }

        private static void ShowErrorDialog(string message)
        {
            MessageBox.Show(message, Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error);
        }

        private void StartServer()
        {
            try
            {
                IPAddress ipAddress = IPAddress.Parse("192.168.1.124");
                serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                serverSocket.Bind(new IPEndPoint(ipAddress, 4545));
                serverSocket.Listen(10);
                serverSocket.BeginAccept(AcceptCallback, null);
            }
            catch (SocketException ex)
            {
                ShowErrorDialog(ex.Message);
            }
            catch (ObjectDisposedException ex)
            {
                ShowErrorDialog(ex.Message);
            }
        }

        private void AcceptCallback(IAsyncResult AR)
        {
            try
            {
                clientSocket = serverSocket.EndAccept(AR);
                buffer = new byte[clientSocket.ReceiveBufferSize];
                var sendData = Encoding.ASCII.GetBytes("Hello");
                clientSocket.BeginSend(sendData, 0, sendData.Length, SocketFlags.None, SendCallback, null);
                clientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, ReceiveCallback, null);
                serverSocket.BeginAccept(AcceptCallback, null);
            }
            catch (SocketException ex)
            {
                ShowErrorDialog(ex.Message);
            }
            catch (ObjectDisposedException ex)
            {
                ShowErrorDialog(ex.Message);
            }
        }

        private void SendCallback(IAsyncResult AR)
        {
            try
            {
                clientSocket.EndSend(AR);
            }
            catch (SocketException ex)
            {
                ShowErrorDialog(ex.Message);
            }
            catch (ObjectDisposedException ex)
            {
                ShowErrorDialog(ex.Message);
            }
        }

        private void ReceiveCallback(IAsyncResult AR)
        {
            try
            {
                Socket current = (Socket)AR.AsyncState;
                int received = clientSocket.EndReceive(AR);

                if (received == 0)
                {
                    return;
                }

                PersonPackage person = new PersonPackage(buffer);
                SubmitPersonToDataGrid(person);

                clientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, ReceiveCallback, null);

                //Added BeginSend which answered my question.  Simple enough fix.  Thanks for looking...
                byte[] sendData = Encoding.ASCII.GetBytes(person.Name);
                clientSocket.BeginSend(sendData, 0, sendData.Length, SocketFlags.None, SendCallback, null);
            }
            catch (SocketException ex)
            {
                ShowErrorDialog(ex.Message);
            }
            catch (ObjectDisposedException ex)
            {
                ShowErrorDialog(ex.Message);
            }
        }

客户代码：

 public partial class ClientForm : Form
    {
        private Socket clientSocket;
        private byte[] buffer;

        public ClientForm()
        {
            InitializeComponent();
        }

        private static void ShowErrorDialog(string message)
        {
            MessageBox.Show(message, Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error);
        }

        private void ReceiveCallback(IAsyncResult AR)
        {
            try
            {
                int received = clientSocket.EndReceive(AR);

                if (received == 0)
                {
                    return;
                }

                string message = Encoding.ASCII.GetString(buffer).TrimEnd('\0');

                Invoke((Action) delegate
                {
                  textBoxEmployee.Text = string.Empty;
                  textBoxEmployee.Text = "Server says: " + message +  " Paul";
                });

                clientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, ReceiveCallback, null);
            }

            catch (SocketException ex)
            {
                ShowErrorDialog(ex.Message);
            }
            catch (ObjectDisposedException ex)
            {
                ShowErrorDialog(ex.Message);
            }
        }

        private void ConnectCallback(IAsyncResult AR)
        {
            try
            {
                clientSocket.EndConnect(AR);
                UpdateControlStates(true);
                buffer = new byte[clientSocket.ReceiveBufferSize];
                clientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, ReceiveCallback, null);
            }
            catch (SocketException ex)
            {
                ShowErrorDialog(ex.Message);
            }
            catch (ObjectDisposedException ex)
            {
                ShowErrorDialog(ex.Message);
            }
        }

        private void SendCallback(IAsyncResult AR)
        {
            try
            {
                clientSocket.EndSend(AR);
            }
            catch (SocketException ex)
            {
                ShowErrorDialog(ex.Message);
            }
            catch (ObjectDisposedException ex)
            {
                ShowErrorDialog(ex.Message);
            }
        }

        private void UpdateControlStates(bool toggle)
        {
            Invoke((Action)delegate
            {
                buttonSend.Enabled = toggle;
                buttonConnect.Enabled = !toggle;
                labelIP.Visible = textBoxAddress.Visible = !toggle;
            });
        }

        private void buttonSend_Click(object sender, EventArgs e)
        {
            try
            {
                PersonPackage person = new PersonPackage(checkBoxMale.Checked, (ushort)numberBoxAge.Value, textBoxEmployee.Text);
                byte[] buffer = person.ToByteArray();
                clientSocket.BeginSend(buffer, 0, buffer.Length, SocketFlags.None, SendCallback, null);
            }
            catch (SocketException ex)
            {
                ShowErrorDialog(ex.Message);
                UpdateControlStates(false);
            }
            catch (ObjectDisposedException ex)
            {
                ShowErrorDialog(ex.Message);
                UpdateControlStates(false);
            }
        }

        private void buttonConnect_Click(object sender, EventArgs e)
        {
            try
            {
                clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                // Connect to the specified host.
                var endPoint = new IPEndPoint(IPAddress.Parse(textBoxAddress.Text), 4545);
                clientSocket.BeginConnect(endPoint, ConnectCallback, null);
            }
            catch (SocketException ex)
            {
                ShowErrorDialog(ex.Message);
            }
            catch (ObjectDisposedException ex)
            {
                ShowErrorDialog(ex.Message);
            }
        }
    }

Answer 1

发现问题。将BeginSend 添加到服务器SendCallBack 方法。代码已更新并可以正常工作...