【转】UDP windows下socket编程实例

Server 端程序源代码:
#include <stdio.h>
#include <Winsock2.h>
void main()
{
SOCKET socket1;
//InitWinsock();
WSADATA wsaData;
     int iErrorCode;
     if (WSAStartup(MAKEWORD(2,1),&wsaData)) //调用Windows Sockets DLL
     {
          printf("Winsock无法初始化!\n");
          WSACleanup();
          return;
     }
     printf("服务器开始创建SOCKET。\n");
struct sockaddr_in local;
struct sockaddr_in from;
int fromlen =sizeof(from);
local.sin_family=AF_INET;
local.sin_port=htons(27015); ///监听端口
local.sin_addr.s_addr=INADDR_ANY; ///本机
socket1=socket(AF_INET,SOCK_DGRAM,0);
bind(socket1,(struct sockaddr*)&local,sizeof(local));
while (1)
{
char buffer[1024]="\0";
printf("waiting for message from others-------------\n");
if (recvfrom(socket1,buffer,sizeof(buffer),0,(struct sockaddr*)&from,&fromlen)!=SOCKET_ERROR)
{
printf("Received datagram from %s--%s\n",inet_ntoa(from.sin_addr),buffer);
////给cilent发信息
sendto(socket1,buffer,sizeof(buffer),0,(struct sockaddr*)&from,fromlen);
}
//Sleep(1000);
}
closesocket(socket1);
WSACleanup();   
}
Client端源代码:
#include <stdio.h>
#include <Winsock2.h>
void main()
{
SOCKET socket1;
//InitWinsock();
WSADATA wsaData;
     int iErrorCode;
     if (WSAStartup(MAKEWORD(2,1),&wsaData)) //调用Windows Sockets DLL
     {
          printf("Winsock无法初始化!\n");
          WSACleanup();
          return;
     }
printf("服务器开始创建SOCKET。\n");
struct sockaddr_in server;
int len =sizeof(server);
server.sin_family=AF_INET;
server.sin_port=htons(27015); ///server的监听端口
server.sin_addr.s_addr=inet_addr("221.223.16.32"); ///server的地址
socket1=socket(AF_INET,SOCK_DGRAM,0);
while (1)
{
     char buffer[1024]="\0";
     printf("input message\n");
     scanf("%s",buffer);
//     printf("%s",buffer);
     if (strcmp(buffer,"bye")==0)
     {
         printf("退出!\n");
         Sleep(100);
         closesocket(socket1);
         break;
     }
     if (sendto(socket1,buffer,sizeof(buffer),0,(struct sockaddr*)&server,len)!=SOCKET_ERROR)
     {
         //printf("sending..\n");
         Sleep(100);
         if (recvfrom(socket1,buffer,sizeof(buffer),0,(struct sockaddr*)&server,&len) != SOCKET_ERROR)
         printf("rece from server:%s\n",buffer);
     }
     }
     closesocket(socket1);
     WSACleanup();   

}