C#-Socket监听消息处理

Posted 2020-08-06

TCP/IP：Transmission Control Protocol/Internet Protocol,传输控制协议/因特网互联协议，又名网络通讯协议。简单来说：TCP控制传输数据，负责发现传输的问题，一旦有问题就发出信号，要求重新传输，直到所有数据安全正确地传输到目的地，而IP是负责给因特网中的每一台电脑定义一个地址，以便传输。TCP协议在许多分布式应用程序中进行消息命令传递是必不可少的部分。

TCP通信的三次握手：三次握手(Three-way Handshake)，是指建立一个TCP连接时，需要客户端和服务器总共发送3个包。

1. 第一次握手：客户端发送一个TCP的SYN标志位置1的包指明客户打算连接的服务器的端口，以及初始序号X,保存在包头的序列号(Sequence Number)字段里。
2. 第二次握手：服务器发回确认包(ACK)应答。即SYN标志位和ACK标志位均为1同时，将确认序号(Acknowledgement Number)设置为客户的I S N加1以.即X+1。
3. 第三次握手：客户端再次发送确认包(ACK) SYN标志位为0,ACK标志位为1.并且把服务器发来ACK的序号字段+1,放在确定字段中发送给对方.并且在数据段放写ISN的+1

先看下服务端Socket监听代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;

namespace SocketDome
{
    /// <summary>
    /// 处理Socket监听逻辑
    /// </summary>
    public class SocketProvider
    {
        private static Socket serviceSocketListener; //Socke监听处理请求

        /// <summary>
        /// 开启Socket监听
        /// </summary>
        public static void Init()
        {
            serviceSocketListener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            serviceSocketListener.Bind(new IPEndPoint(IPAddress.Parse("10.0.0.217"), 20000)); //IP和端口应该是可配置
            serviceSocketListener.Listen(1024);
            Thread handleSocket = new Thread(new ThreadStart(HandleSocket));
            handleSocket.Start();
        }

        /// <summary>
        /// 监听链接
        /// </summary>
        private static void HandleSocket()
        {
            while (true)
            {
                try
                {
                    Socket currSocket = serviceSocketListener.Accept();  //为新建连接创建新的 System.Net.Sockets.Socket
                    Thread processThread = new Thread(new ParameterizedThreadStart(ProcessSocket));
                    processThread.Start(currSocket);
                }
                catch { }
            }
        }

        /// <summary>
        /// 处理Socket信息
        /// </summary>
        /// <param name="obj">新建连接创建新Socket对象</param>
        private static void ProcessSocket(object obj)
        {
            Socket currSocket = (Socket)obj;
            try
            {
                byte[] recvBytess = new byte[1048576];
                int recbytes;
                recbytes = currSocket.Receive(recvBytess, recvBytess.Length, 0);
                if (recbytes > 0)
                {
                    var contentStr = Encoding.UTF8.GetString(recvBytess, 0, recbytes);
                    var _order = contentStr.Split(‘~‘);
                    byte[] sendPass = Encoding.UTF8.GetBytes(_order[0].ToUpper() + "#SUCCESS"); //先相应对话，然后去异步处理
                    currSocket.Send(sendPass, sendPass.Length, SocketFlags.None);
                    switch (_order[0].ToUpper())
                    { 
                        case"ADDCACHE":
                            Console.WriteLine("添加缓存消息" + _order[1]);
                           //处理ADDCACHE逻辑
                           Console.WriteLine("写Log日志");
                            break;
                        default :
                            Console.WriteLine("命令错误");
                            Console.WriteLine("写Log日志");
                            break;
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("写Error日志" + ex.Message);
            }
        }
    }
}

这个服务端，监听着客户端发来的命令，格式定义为：命令~参数，在服务端接受到客户端的命令消息后立即回传接到命令并开始处理，进行异步处理避免客户端等待。

下面看下客户端的Socket客户端主动请求服务端代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;

namespace ConsoleApplication7
{
    /// <summary>
    /// Socket Helper
    /// </summary>
    public class SocketHelper
    {
        private string ip;
        private IPEndPoint ex;
        private Socket socket;

        public SocketHelper(string ip, int port)
        {
            socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            this.ip = ip;
            this.ex = new IPEndPoint(IPAddress.Parse(ip), port);
        }

        /// <summary>
        /// Socket 进行连接
        /// </summary>
        /// <returns>连接失败OR成功</returns>
        public bool Socketlink()
        {
            try
            {
                socket.Connect(ex);
                return true;
            }
            catch (Exception ex)
            {
                return false;
            }
        }

        /// <summary>
        /// Socket 发送消息
        /// </summary>
        /// <param name="strmsg">消息</param>
        public void SendVarMessage(string strmsg)
        {
            try
            {
                byte[] msg = System.Text.Encoding.UTF8.GetBytes(strmsg);
                this.socket.Send(msg);
            }
            catch (Exception ex)
            {
                this.socket.Close();
            }
        }

        /// <summary>
        /// Socket 消息回传
        /// </summary>
        /// <returns></returns>
        public string ReceiveMessage()
        {
            try
            {
                byte[] msg = new byte[1048576];
                int recv = socket.Receive(msg);
                this.socket.Close();
                return System.Text.Encoding.UTF8.GetString(msg, 0, recv);
            }
            catch (Exception ex)
            {
                this.socket.Close();
                return "ERROR";
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication7
{
    class Program
    {
        static void Main(string[] args)
        {
            SocketHelper socket = new SocketHelper("10.0.0.217",20000);
            if(socket.Socketlink())
            {
                Console.WriteLine("连接成功");
                socket.SendVarMessage("ADDCACHE~张三");
                string strReposon = socket.ReceiveMessage();
                Console.WriteLine(strReposon);
            }
            Console.Read();
        }
    }
}

首先以管理园身份开启服务端查询，然后客户端主动请求服务端进行消息请求。