UDP通信C++实现

UDP客户端与服务器端通信模型：

 

服务器端实现：

#include<iostream>
#include<Winsock2.h>
#pragma comment(lib,"WS2_32")
using namespace std;
void main()
{
    WORD wVersionRequested;
 WSADATA wsaData;
 int err;
 
 wVersionRequested = MAKEWORD( 1, 1 );
 
 err = WSAStartup( wVersionRequested, &wsaData );
 if ( err != 0 ) {
  return;
 }
 

 if ( LOBYTE( wsaData.wVersion ) != 1 ||
        HIBYTE( wsaData.wVersion ) != 1 ) {
  WSACleanup( );
  return;
 }

 SOCKET sockSrv=socket(AF_INET,SOCK_DGRAM,0);
 SOCKADDR_IN addrSrv;
 addrSrv.sin_addr.S_un.S_addr=htonl(INADDR_ANY);
 addrSrv.sin_family=AF_INET;
 addrSrv.sin_port=htons(6000);

 bind(sockSrv,(SOCKADDR*)&addrSrv,sizeof(SOCKADDR));

 SOCKADDR_IN addrClient;
 int len=sizeof(SOCKADDR);
 char recvBuf[100];

 recvfrom(sockSrv,recvBuf,100,0,(SOCKADDR*)&addrClient,&len);
 cout<<recvBuf<<endl;
 closesocket(sockSrv);
 WSACleanup();
}

客户端实现：

#include<iostream>
#include<Winsock2.h>
#pragma comment(lib,"WS2_32")
using namespace std;
void main()
{
 WORD wVersionRequested;
 WSADATA wsaData;
 int err;
 
 wVersionRequested = MAKEWORD( 1, 1 );
 
 err = WSAStartup( wVersionRequested, &wsaData );
 if ( err != 0 ) {
  return;
 }
 

 if ( LOBYTE( wsaData.wVersion ) != 1 ||
        HIBYTE( wsaData.wVersion ) != 1 ) {
  WSACleanup( );
  return;
 }

 SOCKET sockClient=socket(AF_INET,SOCK_DGRAM,0);
 SOCKADDR_IN addrSrv;
 addrSrv.sin_addr.S_un.S_addr=inet_addr("127.0.0.1");
 addrSrv.sin_family=AF_INET;
 addrSrv.sin_port=htons(6000);

 sendto(sockClient,"Hello",strlen("Hello")+1,0,
  (SOCKADDR*)&addrSrv,sizeof(SOCKADDR));
 closesocket(sockClient);
 WSACleanup();
}