windows平台下基于UDP的socket编程

#include<WINSOCK2.H> #include<stdio.h> #include<stdlib.h> #pragma comment(lib, "WS2_32.lib") int main() { WSADATA wsadata; //WSADATA变量，用于初始化windows socket SOCKET RecvSocket; //发送消息的SOCKET SOCKADDR_IN RecvAddr; //服务器端地址 u_short port = 8805; //服务器端监听地址 char RecvBuf[1024]; //发送数据的缓冲区 int BufLen = 1024; //缓冲区大小 SOCKADDR_IN SenderAddr; //客户端的地址 int SenderAddrSize = sizeof(SenderAddr); int retVal = -1; int i; //初始化winsock WSAStartup(MAKEWORD(2, 2), &wsadata); //创建接收数据包的socket RecvSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); //设置本机地址和端口 RecvAddr.sin_family = AF_INET; RecvAddr.sin_port = htons(port); RecvAddr.sin_addr.s_addr = inet_addr("127.0.0.1"); //将socket与指定端口和IP绑定 retVal = bind(RecvSocket, (SOCKADDR *)&RecvAddr, sizeof(RecvAddr)); if (SOCKET_ERROR == retVal) { printf("bind failed\n"); closesocket(RecvSocket); WSACleanup(); return -1; } else printf("bind success\n"); //接收数据 printf("Recving data:\n"); while (TRUE) { retVal = recvfrom(RecvSocket, RecvBuf, BufLen, 0, (SOCKADDR *)&SenderAddr, &SenderAddrSize); if (SOCKET_ERROR == retVal) { printf("recv failed !\n"); closesocket(RecvSocket); WSACleanup(); return -2; } else//打印接收到的数据 { printf("retVal=%d\n", retVal); for (i = 0; RecvBuf[i]!='\0'; i++) printf("%c", RecvBuf[i]); printf("\n"); } //将收到的数据回复给客户端 printf("send data to client:\n"); retVal = sendto(RecvSocket, RecvBuf, BufLen, 0, (SOCKADDR *)&SenderAddr, SenderAddrSize); if (SOCKET_ERROR == retVal) { printf("send failed !\n"); closesocket(RecvSocket); WSACleanup(); return -3; } else//打印发给客户端的数据 { printf("retVal=%d\n", retVal); for (i = 0; RecvBuf[i] != '\0'; i++) printf("%c", RecvBuf[i]); printf("\n"); } } //关闭socket printf("Finished recving data.\n"); closesocket(RecvSocket); WSACleanup(); system("pause"); return 0; }