使用UDP

1.流程

解决版本问题->设置监听端口和地址->bind,完成后在系统进行监听->循环进行recvfrom接受连接并接受信息

2.简单示例

服务端:

// udp服务端.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include<WinSock2.h>
#include <stdio.h>
#include <Windows.h>
#pragma comment(lib,"ws2_32.lib")


int main()
{
    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData))
    {
        printf("版本错误
");
        return -1;
    }
    int len=sizeof(sockaddr);
    char recvBuffer[1024];
    SOCKET server_socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    //SOCKET client_socket;
    SOCKADDR_IN bind_addr;
    SOCKADDR_IN client_addr;

    bind_addr.sin_addr.S_un.S_addr = htonl(ADDR_ANY);
    bind_addr.sin_port = htons(8888);
    bind_addr.sin_family = AF_INET;

    //udp进行bind后开始进行侦听
    if (bind(server_socket, (const sockaddr*)&bind_addr, sizeof(sockaddr)) == SOCKET_ERROR)
    {
        printf("bind error code is %d
", WSAGetLastError());
        return -1;
    }
    __try {
        while (1)
        {
            memset(recvBuffer, 0, 1024);
            recvfrom(server_socket, recvBuffer, 1024, 0, (sockaddr*)&client_addr, &len);
            printf("receive %s from %s %d
", recvBuffer, inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));

        }
    }
    __except (closesocket(server_socket))
    {    }

    WSACleanup();
    return 0;
}

 客户端

#include<WinSock2.h>
#include<stdio.h>
#include<string.h>
#pragma comment(lib,"ws2_32.lib")

void main()
{
    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData))
    {
        printf("版本错误
");
        return;
    }
    int len = 0;
    char sendBuffer[1024];
    SOCKET client_socket=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
    SOCKADDR_IN client_addr;
    client_addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    client_addr.sin_family = AF_INET;
    client_addr.sin_port = htons(8888);
    printf("info : type quit to quit
");
    while (1)
    {
        memset(sendBuffer, 0, 1024);
        printf("输入内容:
");
        scanf("%s", sendBuffer);
        if (strcmp(sendBuffer, "quit")==0)
        {
            printf("quit!
");
            closesocket(client_socket);
            WSACleanup();
            return;
        }
        sendto(client_socket, sendBuffer, strlen(sendBuffer), 0, (const SOCKADDR*)&client_addr, &len);
        
    }


}