[C++] socket - 2 [UDP通信C/S实例]

服务端：

 #include<iostream>
 #include<winsock2.h>
 #include<stdio.h>
 #pragma comment(lib,"WS2_32.lib")//显示连接套接字库
 int main()
 {
     WSADATA data;//定义WSADATA结构体
     WORD w=MAKEWORD(,);//定义版本号
     char sztext[]="Welcome you\r\n";//定义并初始化发送到客户端的字符数组
     ::WSAStartup(w,&data);//初始化套接字库
     SOCKET s;
     s=::socket(AF_INET,SOCK_DGRAM,);
     sockaddr_in addr,addr2;//定义套接字地址结构
     int n=sizeof(addr2);
     char buff[]={};//接收数据缓冲区
     addr.sin_family=AF_INET;//初始化地质结构
     addr.sin_port=htons();
     addr.sin_addr.S_un.S_addr=INADDR_ANY;
     ::bind(s,(sockaddr*)&addr,sizeof(addr));//绑定套接字
     printf("UDP Server already start!\r\n");
     if(::recvfrom(s,buff,,,(sockaddr*)&addr2,&n)!=-)//接收客户端信息
     {
         printf("%s already connect\r\n",inet_ntoa(addr2.sin_addr));
         ::sendto(s,sztext,sizeof(sztext),,(sockaddr*)&addr2,n);//向客户端发送字符数组
         ::closesocket(s);//关闭套接字句柄
         ::WSACleanup();//释放套接字库
     }
     if(getchar())
     {
         return ;
     }
     else
     {
         ::Sleep();
     }
 }

客户端：

 #include<iostream>
 #include<winsock2.h>
 #include<stdio.h>
 #pragma comment(lib,"WS2_32.lib")//显示连接套接字库
 int main()
 {
     WSADATA data;//定义WSADATA结构体
     WORD w=MAKEWORD(,);//定义版本号
     ::WSAStartup(w,&data);//初始化套接字库
     SOCKET s;
     s=::socket(AF_INET,SOCK_DGRAM,);//创建TCP套接字
     sockaddr_in addr,addr2;
     int n=sizeof(addr2);
     char buff[]="Wde";
     char sztext[]={};
     addr.sin_family=AF_INET;//初始化地质结构
     addr.sin_port=htons();
     addr.sin_addr.S_un.S_addr=inet_addr("10.203.117.150");
     printf("UDP Clienct already start\r\n");
     if(::sendto(s,sztext,sizeof(sztext),,(sockaddr*)&addr,n)!=)
     {
         ::recvfrom(s,buff,,,(sockaddr*)&addr2,&n);
         printf("Server say:%s\r\n",buff);
         ::closesocket(s);
         ::WSACleanup();//释放套接字库
     }
     if(getchar())
     {
         return ;
     }
     else
     {
         ::Sleep();
     }
 }