一、說明 使用UDP時(shí)，直接使用API代替控件。 第一個(gè)程序(ReadBufferUdp)使用來接收到緩存中。 "Destino"變量非常重要，假如你從其他地方接收數(shù)據(jù)到Buffer，你必須設(shè)置Destino = 0 并且在以后執(zhí)行的時(shí)候賦值你將要發(fā)送的包的地址給它（after the execution it will have the address which send you the packet.）。 假如你只想從一個(gè)指定的地址接收數(shù)據(jù)，你必須設(shè)置變量Destino = <address>. "gvEncerrar" 用來中止處理過程。(gvEncerrar被設(shè)置為全局變量。) 超時(shí)時(shí)間設(shè)置。"Inicio + 12" = 12 sec of timeout.
第三個(gè)程序是用來預(yù)備WinSock程序。 二、代碼 int ReadBufferUdp(unsigned long *Destino,void *T,int Size) { char Buffer[128]; SOCKADDR_IN SockAddr; int LenSockAddr=sizeof(SOCKADDR_IN); fd_set FdRead; strUCt timeval t_val; int Ret; time_t Inicio = time(NULL); application->PRocessMessages(); if(gvEncerrar) return false; FD_ZERO(&FdRead); FD_SET(gvSocket,&FdRead); t_val.tv_sec=0; t_val.tv_usec=0; while((Ret=select(0,&FdRead,NULL,NULL,&t_val))!=1 && (Inicio + 12) > time(NULL) && !gvEncerrar) { FD_ZERO(&FdRead); FD_SET(gvSocket,&FdRead); t_val.tv_sec=0; t_val.tv_usec=0; Application->ProcessMessages(); } if(Ret != 1) return false; if(recvfrom(gvSocket,Buffer,Size,0,(LPSOCKADDR)&SockAddr,&LenSockAddr)!=Size) return false; if(*Destino == 0) { *Destino = SockAddr.sin_addr.s_addr; } else if(*Destino != SockAddr.sin_addr.s_addr) return false; memcpy(T,Buffer,Size); return true; } int WriteBufferUdp(unsigned long Destino,void *T,int Size) { SOCKADDR_IN SockAddr; int Sent; Application->ProcessMessages(); SockAddr.sin_family = AF_INET; SockAddr.sin_port = gvPortUdp; SockAddr.sin_addr.s_addr = Destino; Sent = sendto(gvSocket,(char *)T,Size,0,(LPSOCKADDR)&SockAddr,sizeof(SockAddr)); if(Sent != Size) return false; else return true; } void InicializaTCPip() { Word wVersionRequested; WSADATA wsaData; IN_ADDR In; PSERVENT PServent; SOCKADDR_IN SockAddrIn; wVersionRequested = MAKEWORD( 1, 1 ); if(WSAStartup( wVersionRequested, &wsaData )) { ShowMessage("Erro na inicializao do TCP/IP"); Application->Terminate(); return; } // Get the port on service file if((PServent=getservbyname("your_service_name","udp"))==NULL) { ShowMessage("Erro oBTendo port do servi transurb/udp"); Application->Terminate(); return; } gvPortUdp = PServent->s_port; sprintf(StrAux,"Servi transurb/udp port:%d",ntohs(gvPortUdp)); Log(StrAux); // Open de Socket if((gvSocket = socket(AF_INET,SOCK_DGRAM,0))==INVALID_SOCKET) { ShowMessage("Erro na criao do socket"); Application->Terminate(); return; } Log("Socket criado com sucesso"); // Do the bind SockAddrIn.sin_family = AF_INET; SockAddrIn.sin_port = gvPortUdp; SockAddrIn.sin_addr.s_addr = NULL; if(bind(gvSocket,(LPSOCKADDR)&SockAddrIn,sizeof(SockAddrIn))==SOCKET_ERROR) { ShowMessage("Erro no bind do socket"); Application->Terminate(); return; } Log("Bind do socket com sucesso"); }
