Windows网络编程 TCP/IP模型

主机流程：

1，建立流式套接字

2，与本地地址绑定

3，通知TCP服务器准备好连接

4，等待客户端的连接

5，建立连接

6，在套接字上读/写数据

7，关闭套接字

8，关闭最初的套接字，关闭服务

代码：

// 服务器端.cpp : 定义控制台应用程序的入口点。
#include "stdafx.h"
#define sizeN 225

#include "winsock2.h" //WinSock2的头文件winsock2.h
#pragma comment(lib, "ws2_32.lib") //导入库文件ws2_32.lib，链接WinSock导入库
#include<iostream>
using namespace std;

int main()
{
   WSADATA wsaData; //指向WASDATA结构体变量的指针
   WORD wVersion = MAKEWORD(2, 2); //版本号
   if (WSAStartup(wVersion, &wsaData) != 0) //加载WinSock动态链接库
   {
       cout << "加载winsock.dll失败！\n";
       return 0;
   }

   //用于创建与指定的服务提供者进行绑定
   SOCKET hServer;
   hServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
   if (hServer == INVALID_SOCKET)
   {
       cout << "创建套接字失败！\n";
       closesocket(hServer);
       WSACleanup();
       return 0;
   }

   //绑定（bind函数）
   sockaddr_in addrServer;
   addrServer.sin_family = AF_INET;
   addrServer.sin_port = htons(8000);
   addrServer.sin_addr.s_addr = htonl(INADDR_ANY);

   int nRet = bind(hServer, (LPSOCKADDR)&addrServer, sizeof(addrServer));
   if (nRet == SOCKET_ERROR) //绑定地址套接字：sockaddr结构指针：缓冲区长度
   {
       printf("邦定失败！\n");
       closesocket(hServer);
       WSACleanup();
       return 0;
   }

   //监听
   nRet = listen(hServer, 10);
   if (nRet == SOCKET_ERROR)
   {
       cout << "监听失败";
       closesocket(hServer);
       WSACleanup();
       return 0;
   }

   //接受来自客户端请求
   SOCKET hClient;
   sockaddr_in addrClient;
   int nlen = sizeof(addrClient);
   hClient = accept(hServer, (sockaddr *)&addrClient, &nlen);
   if (hClient == INVALID_SOCKET)
   {
       cout << "错误";
       closesocket(hServer);
       WSACleanup();
       return 0;
   }

   //接受客户端数据
   char szbuf[sizeN];
   while (true)
   {
       memset(szbuf, 0, sizeN);
       nRet = recv(hClient, szbuf, sizeN, 0);
       if (nRet == SOCKET_ERROR)
       {
           cout << "recv 错误";
           closesocket(hClient);
           closesocket(hServer);
           WSACleanup();
           return 0;
       }

       char sPrintbuf[sizeN];
       sprintf_s(sPrintbuf, "IP:%s,接收的信息:%s\n", inet_ntoa(addrClient.sin_addr), szbuf);
       cout << sPrintbuf;

       //发送给客户端数据
       if (strcmp(szbuf, "close") == 0)
       {
           nRet = send(hClient, "close", strlen("close"),0);
       }
       else
       {
           sprintf_s(sPrintbuf, "服务器已经接收到的消息，%s", szbuf);
           nRet = send(hClient, sPrintbuf, strlen(sPrintbuf)+1, 0);
           if (SOCKET_ERROR==nRet)
           {
               cout << "send 出错\n";
               closesocket(hClient);
               closesocket(hServer);
               WSACleanup();
           }
       }
   }
   closesocket(hClient);
   closesocket(hServer);
   WSACleanup();
   getchar();
   getchar();
   return 0;
}

客户端流程：

1，建立流式套接字

2，将套接字与主机连接

3，在套接字上读/写数据

4，关闭套接字，结束服务

代码：

// 服务器端.cpp : 定义控制台应用程序的入口点。
#include "stdafx.h"
#define sizeN 225

#include "winsock2.h" //WinSock2的头文件winsock2.h
#pragma comment(lib, "ws2_32.lib") //导入库文件ws2_32.lib，链接WinSock导入库
#include<iostream>
using namespace std;

   //用于创建与指定的服务提供者进行连接
   SOCKET hClient;
   hClient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
   if (hClient == INVALID_SOCKET)
   {
       cout << "创建套接字失败！\n";
       closesocket(hClient);
       WSACleanup();
       return 0;
   }

   //连接（connect函数）
   sockaddr_in addrClient;
   addrClient.sin_family = AF_INET;
   addrClient.sin_port = htons(8000);
   addrClient.sin_addr.s_addr = inet_addr("127.0.0.1");
   if (connect(hClient, (const sockaddr*)&addrClient, sizeof(addrClient)) < 0) //连接
   {
       cout << "连接失败\n";
       WSACleanup();
       return 0;
   }
   while (1)
   {
       int nRet;
       char szbuf[sizeN];
       cout << "发送消息：";
       cin >> szbuf;
       nRet = send(hClient, szbuf, strlen(szbuf) + 1, 0); //发送信息
       if (SOCKET_ERROR == nRet)
       {
           cout << "send 出错\n";
           closesocket(hClient);
           WSACleanup();
       }

       nRet = recv(hClient, szbuf,sizeN, 0); //接收信息
       if (nRet == SOCKET_ERROR)
       {
           cout << "recv 错误";
           closesocket(hClient);
           WSACleanup();
           return 0;
       }
       cout << szbuf << endl<<endl;
   }

   closesocket(hClient);
   WSACleanup();
   getchar();
   return 0;
}