//服务端
#include <WinSock2.h>
#include <WS2tcpip.h>
#include <iostream>
using namespace std;
#pragma comment(lib, "ws2_32.lib")
#define PORT 65432
DWORD WINAPI ThreadFun(LPVOID lpThreadParameter);
int main()
{
	//初始化winsock2.DLL
	WSADATA wsaData;
	WORD wVersionRequested = MAKEWORD(2, 2);
	if (WSAStartup(wVersionRequested, &wsaData) != 0)
	{
		cout << "加载winsock.dll失败！" << endl;
		return 0;
	}
	//创建套接字
	SOCKET  sock_server;
	if ((sock_server = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
	{
		cout << "创建套接字失败！错误代码：" << WSAGetLastError() << endl;
		WSACleanup();
		return 0;
	}
	//绑定端口和Ip
	sockaddr_in addr;
	addr.sin_family = AF_INET;
	addr.sin_port = htons(PORT);
	inet_pton(AF_INET, "100.4.5.6", &addr.sin_addr);
	if (SOCKET_ERROR == bind(sock_server, (SOCKADDR*)&addr, sizeof(sockaddr_in)))
	{
		cout << "地址绑定失败！错误代码：" << WSAGetLastError() << endl;
		closesocket(sock_server);
		WSACleanup();
		return 0;
	}
	//将套接字设为监听状态
	listen(sock_server, 0);

	//主线程循环接收客户端的连接
	while (1)
	{
		sockaddr_in addrClient;
		int len = sizeof(sockaddr_in);
		//接收成功返回与client通讯的socket
		SOCKET con = accept(sock_server, (SOCKADDR*)&addrClient, &len);
		if (con != INVALID_SOCKET)
		{
			//创建线程 并且传入与client通讯的套接字
			HANDLE hThread = CreateThread(NULL, 0, ThreadFun, (LPVOID)con, 0, NULL);
			CloseHandle(hThread); //关闭对线程的引用
		}
	}
	closesocket(sock_server);
	WSACleanup();
	return 0;
}
//线程通讯部分
DWORD WINAPI ThreadFun(LPVOID lpThreadParameter)
{
	//与客户端通讯 先发送再接收数据
	SOCKET sock = (SOCKET)lpThreadParameter;
	cout << "成功和" << sock << "建立连接！" << endl;
	while (1)
	{
		char msgbuffer[1000];//字符缓冲区
		printf("服务器向%d发送数据：\n", sock);
		cin.getline(msgbuffer, sizeof(msgbuffer));
		int size = send(sock, msgbuffer, sizeof(msgbuffer), 0);//给客户端发送一段信息
		if (strcmp(msgbuffer, "end\0") == 0)
		{
			cout << "关闭和" << sock << "的连接！" << endl;
			return 0;
		}
		if (size == SOCKET_ERROR || size == 0)
		{
			cout << "发送信息失败！错误代码：" << WSAGetLastError() << endl;
			return 0;
		}
		else cout << "信息发送成功！" << endl;

		//接收客户端数据
		msgbuffer[999] = { 0 };
		int ret = recv(sock, msgbuffer, sizeof(msgbuffer), 0);
		if (ret == SOCKET_ERROR || ret == 0)
		{
			cout << sock << "断开了连接！" << endl;
			break;
		}
		else cout << sock << "  说: " << msgbuffer << endl;
	}
	return 0;
}

//客户端
#include <winsock2.h>
#include <WS2tcpip.h>
#include <iostream>
using  namespace std;
#pragma comment(lib, "ws2_32.lib")
#define PORT 65432
int  main()
{
	//初始化winsock2.DLL
	WSADATA wsaData;
	WORD wVersionRequested = MAKEWORD(2, 2);
	if (WSAStartup(wVersionRequested, &wsaData) != 0)
	{
		cout << "加载winsock.dll失败！" << endl;
		return 0;
	}
	//创建套接字
	SOCKET  sock_client;
	if ((sock_client = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
	{
		cout << "创建套接字失败！错误代码：" << WSAGetLastError() << endl;
		WSACleanup();
		return 0;
	}
	//连接服务器
	sockaddr_in   addr;
	addr.sin_family = AF_INET;
	addr.sin_port = htons(PORT);
	inet_pton(AF_INET, "100.4.5.6", &addr.sin_addr);
	int len = sizeof(sockaddr_in);
	if (connect(sock_client, (SOCKADDR*)&addr, len) == SOCKET_ERROR) {
		cout << "连接失败！错误代码：" << WSAGetLastError() << endl;
		return 0;
	}
	//实现交互部分，客户端先接收后发送数据
	while (1)
	{
		//接收服务端的消息
		char msgbuffer[1000] = { 0 };
		int size = recv(sock_client, msgbuffer, sizeof(msgbuffer), 0);
		if (strcmp(msgbuffer, "end\0") == 0)
		{
			cout << "服务器端已经关闭连接！" << endl;
			break;
		}
		if (size < 0)
		{
			cout << "接收信息失败！错误代码：" << WSAGetLastError() << endl;
			break;
		}
		else if (size == 0)
		{
			cout << "对方已经关闭连接" << endl;
			break;
		}
		else cout << "The message from Server:" << msgbuffer << endl;

		//从键盘输入一行文字发送给服务器
		msgbuffer[999] = 0;
		cout << "从键盘输入发给服务器的信息：" << endl;
		cin.getline(msgbuffer, sizeof(msgbuffer));
		if (strcmp(msgbuffer, "end\0") == 0)
		{
			cout << "关闭连接！" << endl;
			break;
		}
		int ret = send(sock_client, msgbuffer, sizeof(msgbuffer), 0);
		if (ret == SOCKET_ERROR || ret == 0)
		{
			cout << "发送信息失败！错误代码：" << WSAGetLastError() << endl;
			break;
		}
		else cout << "信息发送成功！" << endl;
	}
	closesocket(sock_client);
	WSACleanup();
	return 0;
}

错误代码：10049