C++使用UDP通讯的实现示例

#pragma once
#include <Winsock.h>
#pragma comment(lib,"WS2_32.lib")

#define LOCAL_IP_ADDR      INADDR_ANY      //当前应用程序接收的IP地址
#define LOCAL_PORT         9527            //当前应用程序的端口

#define DEST_IP_ADDR       "127.0.0.1"     //目标应用程序的IP地址
#define DEST_PORT          9526            //目标应用程序的端口

class UDP
{
public:
	UDP();
	~UDP();
	void setLocalSockAddr(unsigned long localAddr, const int localPort);  //设置当前应用程序的IP地址和端口
	void setDestSockAddr(const char* destAddr, const int destPort);       //设置目标应用程序的IP地址和端口
	int sendData(char* buf, int len);
	int recvData(char* buf, int len);

private:
	WSADATA m_wsaData;
	SOCKET m_Socket;
	sockaddr_in m_localSockAddr; //当前应用程序的sockaddr_in结构体
	sockaddr_in m_destSockAddr;  //目标应用程序的sockaddr_in结构体
};

#include "udp.h"

UDP::UDP()
{
	WSAStartup(MAKEWORD(2, 2), &m_wsaData);
	m_Socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

	//将socket设为非阻塞模式
	u_long mode = 1;
	ioctlsocket(m_Socket, FIONBIO, &mode);

	//设置当前程序和目标程序的配置
	setLocalSockAddr(LOCAL_IP_ADDR, LOCAL_PORT);
	setDestSockAddr(DEST_IP_ADDR, DEST_PORT);
}

UDP::~UDP()
{
	closesocket(m_Socket);
	WSACleanup();
}

//设置当前应用程序的IP地址和端口
void UDP::setLocalSockAddr(unsigned long localAddr, const int localPort)
{
	//当前应用程序的配置
	m_localSockAddr.sin_family = AF_INET;
	m_localSockAddr.sin_addr.s_addr = htonl(localAddr);
	m_localSockAddr.sin_port = htons(localPort);
	//绑定当前应用程序套接字
	bind(m_Socket, (SOCKADDR*)&m_localSockAddr, sizeof(m_localSockAddr));
}

//设置目标应用程序的IP地址和端口
void UDP::setDestSockAddr(const char * destAddr, const int destPort)
{
	//目标应用程序的配置
	m_destSockAddr.sin_family = AF_INET;
	m_destSockAddr.sin_addr.s_addr = inet_addr(destAddr);
	m_destSockAddr.sin_port = htons(destPort);
}

int UDP::sendData(char * buf, int len)
{
	int ret = sendto(m_Socket, buf, len, 0, (SOCKADDR*)&m_destSockAddr, sizeof(m_destSockAddr));
	return ret;
}

int UDP::recvData(char* buf, int len)
{
	int sockAddrSize = sizeof(sockaddr_in);
	int ret = recvfrom(m_Socket, buf, len, 0, (SOCKADDR*)&m_localSockAddr, &sockAddrSize);
	return ret;
}

#include <iostream>
#include "udp.h"

int main()
{
	UDP udp;
	while (1)
	{
		char buf[1024];
		int ret = udp.recvData(buf, 1024);
		if (ret > 0)
		{
			std::cout << "server recv: " << buf << std::endl;
		}
		else
		{
			std::cout << "server recv: " << "recv failed" << std::endl;
		}
		Sleep(1000);
	}

	return 0;
}

#define LOCAL_IP_ADDR      INADDR_ANY      //当前应用程序接收的IP地址
#define LOCAL_PORT         9527            //当前应用程序的端口

#define DEST_IP_ADDR       "127.0.0.1"     //目标应用程序的IP地址
#define DEST_PORT          9526            //目标应用程序的端口

#include <iostream>
#include "udp.h"

int main()
{
	UDP udp;
	while (1)
	{
		char buf[1024] = "hello udp...";
		udp.sendData(buf, 1024);
		std::cout << "client send: " << buf << std::endl;
		Sleep(1000);
	}
	
	return 0;
}