c++ udp 程序（含服务端和客户端源码）

#include "iostream" #include <winsock2.h> #pragma comment(lib,"ws2_32.lib") using namespace std; #define Const_BufLength 1024 #define Const_Port 12345 BOOL InitSocket(void); WSADATA wsaData; SOCKET m_socket; sockaddr_in SerAdd,CliAdd; int main() { if(!InitSocket()) { cout<<"套接字初始化出错，即将退出"<<endl; WSACleanup(); system("pause"); return -1; } int iLength=sizeof(CliAdd); int retval; char strSendMsg[Const_BufLength]; char strRecvMsg[Const_BufLength]; while(1) { cout<<"等待客户端回应"<<endl; memset(strRecvMsg,0,sizeof(strRecvMsg)); retval=recvfrom(m_socket,strRecvMsg,Const_BufLength,0,(SOCKADDR*)&CliAdd,&iLength); if(retval==SOCKET_ERROR) { cout<<"接受失败，错误ID为："<<WSAGetLastError()<<endl; break; } else if(retval==0) { break; } else { cout<<"IP:Port\t"<<inet_ntoa(CliAdd.sin_addr)<<":"<<ntohs(CliAdd.sin_port)<<'\t'<<strRecvMsg<<endl; } memset(strSendMsg,0,sizeof(strSendMsg)); cout<<"收到客户消息，直接转发消息"<<endl; strcpy(strSendMsg,strRecvMsg); if(strcmp(strSendMsg,"exit")==0) { strcpy(strSendMsg,"收到客户下线的消息，我是服务器，我也下线了"); retval=sendto(m_socket,strSendMsg,sizeof(strSendMsg),0,(SOCKADDR*)&CliAdd,sizeof(CliAdd)); closesocket(m_socket); WSACleanup(); return 0; } retval=sendto(m_socket,strSendMsg,sizeof(strSendMsg),0,(SOCKADDR*)&CliAdd,sizeof(CliAdd)); if(retval==SOCKET_ERROR) { cout<<"发送失败，错误ID为："<<WSAGetLastError()<<endl; break; } else if(retval==0) { break; } else { cout<<"发送成功!"<<endl; } } closesocket(m_socket); WSACleanup(); return 0; } BOOL InitSocket(void) { if(WSAStartup(MAKEWORD(2,2),&wsaData)!=0) { cout<<"加载winsock失败，错误ID为："<<WSAGetLastError()<<endl; exit(0); } m_socket=socket(AF_INET,SOCK_DGRAM,0); if(INVALID_SOCKET==m_socket) { cout<<"套接字创建失败！错误ID为："<<WSAGetLastError()<<endl; return FALSE; } SerAdd.sin_family=AF_INET; SerAdd.sin_port=htons(Const_Port); SerAdd.sin_addr.S_un.S_addr=htonl(INADDR_ANY); int retval; retval=bind(m_socket,(SOCKADDR*)&SerAdd,sizeof(SOCKADDR)); if(SOCKET_ERROR==retval) { closesocket(m_socket); cout<<"端口绑定失败! 错误ID为："<<WSAGetLastError()<<endl; return FALSE; } return TRUE; }