Windows socket通信（一个简单的客户端和服务器的收发）

服务器代码：

#define WIN32_LEAN_AND_MEAN
#define _WINSOCK_DEPRECATED_NO_WARNINGS

#include<windows.h>
#include<WinSock2.h>
#include<stdio.h>

#pragma comment(lib,"ws2_32.lib")

enum CMD
{
	CMD_LOGIN,
	CMD_LOGIN_RESULT,
	CMD_LOGOUT,
	CMD_LOGOUT_RESULT,
	CMD_ERROR
};
struct DataHeader
{
	short dataLength;
	short cmd;
};
//DataPackage
struct Login: public DataHeader
{
	Login()
	{
		dataLength = sizeof(Login);
		cmd = CMD_LOGIN;
	}
	char userName[32];
	char PassWord[32];
};

struct LoginResult : public DataHeader
{
	LoginResult()
	{
		dataLength = sizeof(LoginResult);
		cmd = CMD_LOGIN_RESULT;
		result = 0;
	}
	int result;
};

struct Logout : public DataHeader
{
	Logout()
	{
		dataLength = sizeof(Logout);
		cmd = CMD_LOGOUT;
	}
	char userName[32];
};

struct LogoutResult : public DataHeader
{
	LogoutResult()
	{
		dataLength = sizeof(LogoutResult);
		cmd = CMD_LOGIN_RESULT;
		result = 0;
	}
	int result;
};

int main()
{
	//启动Windows socket 2.x环境
	WORD ver = MAKEWORD(2, 2);
	WSADATA dat;
	WSAStartup(ver, &dat);
	//------------

	//-- 用Socket API建立简易TCP服务端
	// 1 建立一个socket 套接字
	SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	// 2 bind 绑定用于接受客户端连接的网络端口
	sockaddr_in _sin = {};
	_sin.sin_family = AF_INET;
	_sin.sin_port = htons(4567);//host to net unsigned short
	_sin.sin_addr.S_un.S_addr = INADDR_ANY;//inet_addr("127.0.0.1");
	if (SOCKET_ERROR == bind(_sock, (sockaddr*)&_sin, sizeof(_sin)))
	{
		printf("错误,绑定网络端口失败...\n");
	}
	else {
		printf("绑定网络端口成功...\n");
	}
	// 3 listen 监听网络端口
	if (SOCKET_ERROR == listen(_sock, 5))
	{
		printf("错误,监听网络端口失败...\n");
	}
	else {
		printf("监听网络端口成功...\n");
	}
	// 4 accept 等待接受客户端连接
	sockaddr_in clientAddr = {};
	int nAddrLen = sizeof(sockaddr_in);
	SOCKET _cSock = INVALID_SOCKET;

	_cSock = accept(_sock, (sockaddr*)&clientAddr, &nAddrLen);
	if (INVALID_SOCKET == _cSock)
	{
		printf("错误,接受到无效客户端SOCKET...\n");
	}
	printf("新客户端加入：socket = %d,IP = %s \n", (int)_cSock, inet_ntoa(clientAddr.sin_addr));


	while (true)
	{
		DataHeader header = {};
		// 5 接收客户端数据
		int nLen = recv(_cSock, (char*)&header, sizeof(DataHeader), 0);
		if (nLen <= 0)
		{
			printf("客户端已退出，任务结束。");
			break;
		}
		switch (header.cmd)
		{
			case CMD_LOGIN:
				{
					Login login = {};
					recv(_cSock, (char*)&login+sizeof(DataHeader), sizeof(Login)-sizeof(DataHeader), 0);
					printf("收到命令：CMD_LOGIN,数据长度：%d,userName=%s PassWord=%s\n", login.dataLength, login.userName, login.PassWord);
					//忽略判断用户密码是否正确的过程
					LoginResult ret;
					send(_cSock, (char*)&ret, sizeof(LoginResult), 0);
				}
				break;
			case CMD_LOGOUT:
				{
					Logout logout = {};
					recv(_cSock, (char*)&logout+sizeof(DataHeader), sizeof(logout)- sizeof(DataHeader), 0);
					printf("收到命令：CMD_LOGOUT,数据长度：%d,userName=%s \n", logout.dataLength, logout.userName);
					//忽略判断用户密码是否正确的过程
					LogoutResult ret;
					send(_cSock, (char*)&ret, sizeof(ret), 0);
				}
				break;
			default:
				header.cmd = CMD_ERROR;
				header.dataLength = 0;
				send(_cSock, (char*)&header, sizeof(header), 0);
			break;
		}
\
	}
	// 8 关闭套节字closesocket
	closesocket(_sock);
	//------------
	//清除Windows socket环境
	WSACleanup();
	printf("已退出。");
	getchar();
	return 0;
}

客户端代码：

#define WIN32_LEAN_AND_MEAN

#include<windows.h>
#include<WinSock2.h>
#include<stdio.h>

#pragma comment(lib,"ws2_32.lib")

enum CMD
{
	CMD_LOGIN,
	CMD_LOGIN_RESULT,
	CMD_LOGOUT,
	CMD_LOGOUT_RESULT,
	CMD_ERROR
};
struct DataHeader
{
	short dataLength;
	short cmd;
};
//DataPackage
struct Login : public DataHeader
{
	Login()
	{
		dataLength = sizeof(Login);
		cmd = CMD_LOGIN;
	}
	char userName[32];
	char PassWord[32];
};

struct LoginResult : public DataHeader
{
	LoginResult()
	{
		dataLength = sizeof(LoginResult);
		cmd = CMD_LOGIN_RESULT;
		result = 0;
	}
	int result;
};

struct Logout : public DataHeader
{
	Logout()
	{
		dataLength = sizeof(Logout);
		cmd = CMD_LOGOUT;
	}
	char userName[32];
};

struct LogoutResult : public DataHeader
{
	LogoutResult()
	{
		dataLength = sizeof(LogoutResult);
		cmd = CMD_LOGIN_RESULT;
		result = 0;
	}
	int result;
};


int main()
{
	//启动Windows socket 2.x环境
	WORD ver = MAKEWORD(2, 2);
	WSADATA dat;
	WSAStartup(ver, &dat);
	//------------
	//-- 用Socket API建立简易TCP客户端
	// 1 建立一个socket
	SOCKET _sock = socket(AF_INET, SOCK_STREAM, 0);
	if (INVALID_SOCKET == _sock)
	{
		printf("错误，建立Socket失败...\n");
	}
	else {
		printf("建立Socket成功...\n");
	}
	// 2 连接服务器 connect
	sockaddr_in _sin = {};
	_sin.sin_family = AF_INET;
	_sin.sin_port = htons(4567);
	_sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	int ret  = connect(_sock, (sockaddr*)&_sin, sizeof(sockaddr_in));
	if (SOCKET_ERROR == ret)
	{
		printf("错误，连接服务器失败...\n");
	}
	else {
		printf("连接服务器成功...\n");
	}

	
	while (true)
	{
		//3输入请求命令
		char cmdBuf[128] = {};
		scanf("%s",cmdBuf);
		//4 处理请求命令
		if (0 == strcmp(cmdBuf, "exit"))
		{
			printf("收到exit命令，任务结束。\n");
			break;
		}
		else if (0 == strcmp(cmdBuf, "login")) {
			//5 向服务器发送请求命令
			Login login;
			strcpy(login.userName, "lyd");
			strcpy(login.PassWord, "lydmima");
			send(_sock, (const char *)&login, sizeof(login), 0);
			// 接收服务器返回的数据
			LoginResult loginRet = {};
			recv(_sock, (char*)&loginRet, sizeof(loginRet), 0);
			printf("LoginResult: %d \n", loginRet.result);
		}
		else if (0 == strcmp(cmdBuf, "logout")) {
			Logout logout;
			strcpy(logout.userName, "lyd");
			//5 向服务器发送请求命令
			send(_sock, (const char *)&logout, sizeof(logout), 0);
			// 接收服务器返回的数据
			LogoutResult logoutRet = {};
			recv(_sock, (char*)&logoutRet, sizeof(logoutRet), 0);
			printf("LogoutResult: %d \n", logoutRet.result);
		}
		else {
			printf("不支持的命令，请重新输入。\n");
		}
	}
	// 7 关闭套节字closesocket
	closesocket(_sock);
	//清除Windows socket环境
	WSACleanup();
	printf("已退出。");
	getchar();
	return 0;
}