C++ socket UDP網絡編程(簡單聊天室)

0.通信步驟流程圖（左：服務器；右：客戶端；）

 

1.服務器代碼

1.1服務器類頭文件(CServer_UDP.h)

#pragma once

#include <winsock2.h>

class CServer_UDP
{
public:
	CServer_UDP();
	void SendMsg(const char sendBuf[]);
	void RecMsg();
	~CServer_UDP();

private:
	SOCKET m_sServer;
	struct sockaddr_in m_SocAddrClient;		//建立連接時，用於保存客戶端信息
	bool m_terminal;
};

1.2服務器類源文件(CServer_UDP.cpp)

#define _WINSOCK_DEPRECATED_NO_WARNINGS
#include "CServer_UDP.h"

#include <iostream>

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


CServer_UDP::CServer_UDP():m_terminal(false)
{
	//必須進行如下初始化， 否則socket()會返回10093錯誤
	//初始化WSA  
	WORD sockVersion = MAKEWORD(2, 2);
	WSADATA wsaData;
	if (WSAStartup(sockVersion, &wsaData) != 0) //通過一個進程初始化ws2_32.dll
	{
		std::cout << "Initialize WSA failed" << std::endl;
		return;
	}
	//初始化UDDP套接字
	m_sServer = socket(AF_INET, SOCK_DGRAM, 0);

	struct sockaddr_in m_SocAddrserver;
	m_SocAddrserver.sin_addr.S_un.S_addr = 0;//htonl(INADDR_ANY);
	m_SocAddrserver.sin_family = AF_INET;
	m_SocAddrserver.sin_port = htons(8090);

	int ret = bind(m_sServer, (sockaddr*)&m_SocAddrserver, sizeof(m_SocAddrserver));
	if (ret == -1)
	{
		std::cout << "bind failed!" << std::endl;
		WSACleanup();
	}
	else
	{
		//此處必須賦初值，不然會導致服務器端無法正常發送
		int len_Client = sizeof(sockaddr);  
		char recBuf[1025];
		int len = recvfrom(m_sServer, recBuf, 1024, 0, (sockaddr*)&m_SocAddrClient, &len_Client);
		if (len > 0)
		{
			recBuf[len] = '\0';
			std::cout << "Client say:" << recBuf << std::endl;
		}
	}


}
void CServer_UDP::SendMsg(const char sendBuf[])
{
	int ret = sendto(m_sServer, sendBuf, strlen(sendBuf), 0, (sockaddr*)&m_SocAddrClient, sizeof(m_SocAddrClient));
	if (ret == -1)
	{
		std::cout << "send failed" << std::endl;
		std::cout << GetLastError()<< std::endl;
	}
}
void CServer_UDP::RecMsg()
{
	char recBuf[1025];
	while (!m_terminal)
	{
		//std::cout << "Begin rec...(server)" << std::endl;
		int len = recvfrom(m_sServer, recBuf, 1024, 0, 0, 0);
		if (len > 0)
		{
			recBuf[len] = '\0';
			std::cout << "Client say:" << recBuf << std::endl;
		}
	}
	
}
CServer_UDP::~CServer_UDP()
{
	closesocket(m_sServer);
	WSACleanup();

}

1.3服務器主函數

#include <iostream>
#include <thread>
#include <string>

#include "CServer_UDP.h"

using namespace std;

int main()
{
	CServer_UDP server_UDP;

	thread recProc(&CServer_UDP::RecMsg, &server_UDP);

	while (1)
	{
		//cout << "Pleaes input content:" << endl;
		string content;
		cin >> content;
		server_UDP.SendMsg(content.c_str());
	}

	recProc.join();
	cout << "I love china!" << endl;
	system("pause");
	return 0;
}

2.客戶端代碼

2.1客戶端類頭文件(CClient.h)

#pragma once

#include <winsock2.h>

class CClient
{
public:
	CClient();
	void RecMsg();
	void SendMsg(const char sendBuf[]);
	~CClient();
private:
	SOCKET m_sockClient;
	sockaddr_in m_TargetServer;
};

2.2客戶端類源文件(CClient.cpp)

#define _WINSOCK_DEPRECATED_NO_WARNINGS
#include "CClient.h"

#include <iostream>

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

CClient::CClient()
{
	//必須進行如下初始化， 否則socket()會返回10093錯誤
	//初始化WSA  
	WORD sockVersion = MAKEWORD(2, 2);
	WSADATA wsaData;
	if (WSAStartup(sockVersion, &wsaData) != 0) //通過一個進程初始化ws2_32.dll
	{
		std::cout << "Initialize WSA failed" << std::endl;
		return;
	}

	m_sockClient = socket(AF_INET, SOCK_DGRAM, 0);

	m_TargetServer.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	m_TargetServer.sin_family = AF_INET;
	m_TargetServer.sin_port = htons(8090);

	if (m_sockClient == -1)
	{
		std::cout << "Create socket failed!" << std::endl;
		WSACleanup();
	}
	else
	{
		//發送信息與服務器建立連接(必須加)
		sendto(m_sockClient, "hello server", strlen("hello server"), 0, (sockaddr*)&m_TargetServer, sizeof(m_TargetServer));
	}
}

void CClient::SendMsg(const char sendBuf[])
{
	sendto(m_sockClient, sendBuf, strlen(sendBuf), 0, (sockaddr*)&m_TargetServer, sizeof(m_TargetServer));
}
void CClient::RecMsg()
{
	char recBuf[1025];

	while (1)
	{
		//std::cout << "Begin rec...(client)" << std::endl;
		int len = recvfrom(m_sockClient, recBuf, 1024, 0, 0, 0);
		if (len > 0)
		{
			recBuf[len] = '\0';
			std::cout << "Server say: " << recBuf << std::endl;
		}
	}

}
CClient::~CClient()
{
	closesocket(m_sockClient);
	WSACleanup();
}

2.3客戶端主函數

#include <iostream>
#include <string>
#include <thread>

#include "CClient.h"

using namespace std;

int main()
{
	CClient client_UDP;

	thread RecProc(&CClient::RecMsg, &client_UDP);

	while (1)
	{
		//cout << "Please input content:" << endl;
		string content;
		cin >> content;

		client_UDP.SendMsg(content.c_str());
	}


	RecProc.join();
	cout << "I love china!" << endl;
	system("pause");
	return 0;
}

3.效果圖(win7+VS2017)

3.1服務端

3.2客戶端