【C#-Socket监听消息处理】

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。

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。
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。
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);
}
}
}
}

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

namespace SocketDome
{
class Program
{
static void Main(string[] args)
{
//开启Socket监听处理
SocketProvider.Init();
}
}
}

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。