基于UDP的socket编程

UDP服务器代码

/*
* 基于udp的socket编程
*/
 
/*
* udp服务器端代码
*/
 
#include<winsock2.h>
#include<stdio.h>
#include<windows.h>
#include<iostream>
#include<ws2tcpip.h>
 
#pragma comment(lib, "WS2_32.lib")
 
using namespace std;
 
int main()
{
    WSADATA data;                           //定义结构体变量
    WORD w = MAKEWORD(2, 0);               //定义套接字版本
    ::WSAStartup(w, &data);                //初始化套接字库
    SOCKET s;                              //定义套接字句柄
    s = ::socket(AF_INET, SOCK_DGRAM, 0);  //创建UDP套接字
    sockaddr_in addr;                      //套接字地址结构变量
    int n = sizeof(addr);                  //地址结构变量大小
    addr.sin_family = AF_INET;
    addr.sin_port = htons(75);
    addr.sin_addr.S_un.S_addr = INADDR_ANY;
    ::bind(s, (sockaddr*)&addr, sizeof(addr));     //绑定套接字
    cout << "UDP服务器启动..." << endl;
    char buffer[10] = { 0 };
    sockaddr_in addr2;
    char sztext[] = "欢迎你\n";               //发送到客户端的数据
 
    char clientAddr[30];
    while (true)
    {
        //接受客户端的信息
        if (::recvfrom(s, buffer, 10, 0, (sockaddr*)&addr2, &n) != 0)
        {
            cout << "已经连接上" << inet_ntop(AF_INET, &addr2.sin_addr, clientAddr, 30) << endl;
            cout << buffer << endl;
            //发送数据到客户端
            ::sendto(s, sztext, sizeof(sztext), 0, (sockaddr*)&addr2, n);
            break;
        }
    }
 
    ::closesocket(s);
    ::WSACleanup();
 
    if (getchar())
    {
        return 0;
    }
    else
    {
        ::Sleep(100);
    }
 
}

　　UDP客户端代码

/*
* UDP客户端代码
*/
 
#include<winsock2.h>
#include<stdio.h>
#include<windows.h>
#include<iostream>
#include<ws2tcpip.h>
 
#pragma comment(lib, "WS2_32.lib")                  //显示连接套接字库
 
using namespace std;
 
int main()
{
    WSADATA data;
    WORD w = MAKEWORD(2, 0);
    ::WSAStartup(w, &data);
    SOCKET s;
    s = ::socket(AF_INET, SOCK_DGRAM, 0);              //创建UDP套接字
    sockaddr_in addr, addr2;
    int n = sizeof(addr);
    char buff[10] = { 0 };
    addr.sin_family = AF_INET;
    addr.sin_port = htons(75);
    inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr.S_un.S_addr);
    cout << "UDP客户端已启动" << endl;
    char sztext[] = "你好\n";
 
    //发送信息
    if (::sendto(s,sztext,sizeof(sztext), 0, (sockaddr*)&addr, n)!=0)
    {
        ::recvfrom(s, buff, 10, 0, (sockaddr*)&addr2, &n);
        cout << "服务器说：" << buff << endl;
        ::closesocket(s);
        ::WSACleanup();
    }
 
    if (getchar())
    {
        return 0;
    }
    else
    {
        ::Sleep(100);
    }
 
 
}