封装串口类

#include "stdafx.h" #include "CommUtils.h" #include "stdio.h" const int READ_TIMEOUT = 500; CommUtils::CommUtils() { bOpenCom = false; } CommUtils::~CommUtils() { this->CloseCom(); } bool CommUtils::OpenCom(int Port) { if (bOpenCom) { this->CloseCom(); bOpenCom = false; } char szport[10]; sprintf(szport,"COM%d",Port); hComm = CreateFile( szport,GENERIC_READ|GENERIC_WRITE, 0,NULL,OPEN_EXISTING,FILE_FLAG_OVERLAPPED,NULL); int error=GetLastError(); if (hComm == INVALID_HANDLE_VALUE) return false; if (!SetupComm(hComm, 1024, 512)) return false; COMMTIMEOUTS commtimeouts; commtimeouts.ReadIntervalTimeout = MAXDWORD; commtimeouts.ReadTotalTimeoutConstant =0; commtimeouts.ReadTotalTimeoutMultiplier =0; commtimeouts.WriteTotalTimeoutConstant =0; commtimeouts.WriteTotalTimeoutMultiplier=0; if (!SetCommTimeouts(hComm, &commtimeouts)) return false; memset(&ReadovReady,0,sizeof(OVERLAPPED)); memset(&WriteovReady,0,sizeof(OVERLAPPED)); ReadovReady.hEvent = CreateEvent(NULL,TRUE,FALSE,NULL); WriteovReady.hEvent =CreateEvent(NULL,TRUE,FALSE,NULL); SECURITY_ATTRIBUTES sa; sa.nLength=sizeof(SECURITY_ATTRIBUTES); sa.lpSecurityDescriptor=NULL; sa.bInheritHandle=TRUE; DCB dcb; GetCommState(hComm, &dcb); dcb.fBinary = TRUE; dcb.fParity = TRUE; dcb.BaudRate = CBR_9600; // baud rate 9600 dcb.ByteSize = 8; dcb.Parity = NOPARITY; dcb.StopBits = ONESTOPBIT; if (!SetCommState(hComm, &dcb )) return false; bOpenCom = true; return bOpenCom; } bool CommUtils::WriteCom(unsigned char *sendchar, int sendsize) { if (!bOpenCom) return false; DWORD BytesSent; DWORD resD; PurgeComm(hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); BytesSent=0; BOOL hr = WriteFile(hComm, // Handle to COMM Port sendchar, // Pointer to message buffer in calling finction sendsize, // Length of message to send &BytesSent, // Where to store the number of bytes sent &WriteovReady); // Overlapped structure if(!hr) { if(GetLastError() != ERROR_IO_PENDING) { return false; } else { resD=WaitForSingleObject(WriteovReady.hEvent,INFINITE); } switch(resD) { case WAIT_OBJECT_0: { if(!GetOverlappedResult(hComm,&WriteovReady,&BytesSent,false)) return false; else return true; } default: return false; break; } } return true; } void CommUtils::CloseCom() { if (!bOpenCom) return; CloseHandle(hComm); hComm=NULL; CloseHandle(ReadovReady.hEvent); CloseHandle(WriteovReady.hEvent ); ReadovReady.hEvent =NULL; WriteovReady.hEvent =NULL; } bool CommUtils::ReadCom(unsigned char * ReceiveData, DWORD& ReceiveLength) { if (!bOpenCom) return false; if (ReadovReady.hEvent == NULL) return false; ReceiveLength = 0; if (ReadFile(hComm, ReceiveData, 128, &ReceiveLength, &ReadovReady) == FALSE) { if (GetLastError() != ERROR_IO_PENDING) return false; } /* bResult = ReadFile(port->m_hComm, // Handle to COMM port &RXBuff, // RX Buffer Pointer 1, // Read one byte &BytesRead, // Stores number of bytes read &port->m_ov); // pointer to the m_ov structure // deal with the error code */ if(ReceiveLength == 0) return false; ReceiveData[ReceiveLength] = 0; DWORD dwRead; DWORD dwRes = WaitForSingleObject(ReadovReady.hEvent, READ_TIMEOUT); switch(dwRes) { case WAIT_OBJECT_0: if (!GetOverlappedResult(hComm, &ReadovReady, &dwRead, FALSE)) return false; break; case WAIT_TIMEOUT: break; default: break; } return true; }