TCP Socket 客户端异步 - 连接处理

Question

我在 TCP 客户端套接字中的连接处理有问题。

此代码应连接到 localhost 的 4444 端口并侦听来自此 TCP 服务器的所有传入数据。

我需要为此编写连接处理。例如，如果在尝试连接时服务器没有响应，它应该重新尝试连接，或者如果连接已准备好并且在接收到一些数据后 TCP 服务器将关闭连接 TCP 客户端应该重新尝试重新连接。

谁能帮我解决这个问题

这是我此刻所拥有的

using UnityEngine;
using System.Collections;
using System;
using System.Net;
using System.Net.Sockets;

public class TCPClientNew : MonoBehaviour {

    private Socket _clientSocket = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
    private byte[] _recieveBuffer = new byte[8142];

    private void StartClient()
    {
        try
        {
            _clientSocket.Connect(new IPEndPoint(IPAddress.Loopback,4444));
        }
        catch(SocketException ex)
        {
            Debug.Log(ex.Message);

            // Try to reconnect ??  TODO
        }
        Debug.Log ("connected");

        _clientSocket.BeginReceive(_recieveBuffer,0,_recieveBuffer.Length,SocketFlags.None,new AsyncCallback(ReceiveCallback),null);

    }

    private void ReceiveCallback(IAsyncResult AR)
    {
        //Check how much bytes are recieved and call EndRecieve to finalize handshake
        int recieved = _clientSocket.EndReceive(AR);

        if(recieved <= 0)
            return;

        //Copy the recieved data into new buffer , to avoid null bytes
        byte[] recData = new byte[recieved];
        Buffer.BlockCopy(_recieveBuffer,0,recData,0,recieved);


        //Processing received data
        Debug.Log (System.Text.Encoding.ASCII.GetString(recData));



        //Start receiving again
        _clientSocket.BeginReceive(_recieveBuffer,0,_recieveBuffer.Length,SocketFlags.None,new AsyncCallback(ReceiveCallback),null);
    }

    private void SendData(byte[] data)
    {
        SocketAsyncEventArgs socketAsyncData = new SocketAsyncEventArgs();
        socketAsyncData.SetBuffer(data,0,data.Length);
        _clientSocket.SendAsync(socketAsyncData);
    }

    void Start()
    {
        StartClient ();
    }
}

Answer 1

您想要的是一种在连接失败时继续重试连接的方法。如果在读取过程中出现异常，您想查看我们是否仍然连接，如果没有则重新连接。我在 Connect() 方法中添加了一个循环，等待 1 秒后重试连接。

在接收回调中，我放了一个try/catch，如果有异常我会回到Connect()方法重试连接。

public class TCPClientNew
{

    private Socket _clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
    private byte[] _recieveBuffer = new byte[8142];

    private void Connect()
    {
        bool isConnected = false;

        // Keep trying to connect
        while (!isConnected)
        {
            try
            {
                _clientSocket.Connect(new IPEndPoint(IPAddress.Loopback, 4444));
                // If we got here without an exception we should be connected to the server
                isConnected = true;
            }
            catch (SocketException ex)
            {
                Debug.Log(ex.Message);

                // Wait 1 second before trying to connect again
                Thread.Sleep(1000);
            }
        }

        // We are now connected, start to receive
        _clientSocket.BeginReceive(_recieveBuffer, 0, _recieveBuffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), null);
    }

    private void ReceiveCallback(IAsyncResult AR)
    {
        //Check how much bytes are recieved and call EndRecieve to finalize handshake
        try
        {
            int recieved = _clientSocket.EndReceive(AR);

            if (recieved <= 0)
                return;

            //Copy the recieved data into new buffer , to avoid null bytes
            byte[] recData = new byte[recieved];
            Buffer.BlockCopy(_recieveBuffer, 0, recData, 0, recieved);

            //Start receiving again
            _clientSocket.BeginReceive(_recieveBuffer, 0, _recieveBuffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), null);
        }
        catch (SocketException ex)
        {
            Debug.Log(ex.Message);

            // If the socket connection was lost, we need to reconnect
            if (!_clientSocket.Connected)
            {
                Connect();
            }
            else
            {
                //Just a read error, we are still connected
                _clientSocket.BeginReceive(_recieveBuffer, 0, _recieveBuffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), null);
            }
        }
    }

    private void SendData(byte[] data)
    {
        SocketAsyncEventArgs socketAsyncData = new SocketAsyncEventArgs();
        socketAsyncData.SetBuffer(data, 0, data.Length);
        _clientSocket.SendAsync(socketAsyncData);
    }
}