一个用api封装的串口类

#include "stdafx.h" #include "SerialPort.h" CCom::CCom() { m_hCom = NULL; Cnter = 0; memset(&m_OverlappedWrite, 0, sizeof(OVERLAPPED)); memset(&m_OverlappedRead, 0, sizeof(OVERLAPPED)); } CCom::~CCom() { } BOOL CCom::SetComPar(DWORD BaudRate, char WordLength, char StopBits, char Parity) { if(!m_hCom) return FALSE; DCB dcb; dcb.DCBlength = sizeof(DCB); if(!GetCommState(m_hCom, &dcb)) return FALSE; dcb.BaudRate = BaudRate; dcb.ByteSize = WordLength; dcb.Parity = Parity; BYTE stopb = 0; if(StopBits == 1) stopb = 0; else if (StopBits == 2) stopb = 2; dcb.StopBits = stopb; if(!SetCommState(m_hCom, &dcb)) return FALSE; return TRUE; } BOOL CCom::SetCacheSize(DWORD RxCacheSize, DWORD TxCacheSize) { if(!m_hCom){ return FALSE; } if(!SetupComm(m_hCom, RxCacheSize, TxCacheSize)) { return FALSE; } return TRUE; } void CCom::ClearCache() { if(!m_hCom){ return ; } PurgeComm(m_hCom,PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR); } BOOL CCom::OpenPort(const char* Com, DWORD BaudRate, char WordLength, char StopBits, char Parity) { char strport[11]; memset(strport, 0, 11); if(*(Com + 4)){ strcpy(strport, "\\\\.\\COM"); strcpy(strport + 7, Com + 3); }else{ strcpy(strport, Com); } m_hCom = CreateFile(strport, //COM口 GENERIC_READ | GENERIC_WRITE, //允许读和写 0, //独占方式 NULL, OPEN_EXISTING, //打开而不是创建 FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, //重叠方式 NULL ); if(m_hCom == (HANDLE) - 1){ m_hCom = NULL; return FALSE; } if(!SetComPar(BaudRate, WordLength, StopBits, Parity)){ Close(); return FALSE; } if(!SetCacheSize(1024, 1024)){ Close(); return FALSE; } ClearCache(); COMMTIMEOUTS TimeOuts; TimeOuts.ReadIntervalTimeout = 10; TimeOuts.ReadTotalTimeoutConstant = 0; TimeOuts.ReadTotalTimeoutMultiplier = 0; TimeOuts.WriteTotalTimeoutConstant = 100; TimeOuts.WriteTotalTimeoutMultiplier = 500; BOOL sig = SetCommTimeouts(m_hCom, &TimeOuts); m_OverlappedRead.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL ); m_OverlappedWrite.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL ); return TRUE; } int CCom::Send(BYTE *pBuf, DWORD SendByte, DWORD TimeOut) { DWORD dwBeWritten; if(!m_hCom){ return 0; } PurgeComm(m_hCom, PURGE_RXCLEAR); if(!WriteFile(m_hCom, (LPSTR)pBuf, SendByte, &dwBeWritten, &m_OverlappedWrite)){ if(GetLastError() == ERROR_IO_PENDING){ DWORD Result = WaitForSingleObject(m_OverlappedWrite.hEvent, TimeOut); if(WAIT_TIMEOUT == Result || WAIT_OBJECT_0 == Result){ GetOverlappedResult(m_hCom, &m_OverlappedWrite, &dwBeWritten, FALSE); } } else { dwBeWritten = 0; } } if(dwBeWritten == SendByte){ PurgeComm(m_hCom, PURGE_TXCLEAR); } return (int)dwBeWritten; //返回实际写入的字节数 } //extend read option, if Flag == TRUE, clear the receive buffer before return. int CCom::ReadEX(BYTE *pBuf, DWORD ReadByte, DWORD TimeOut, int Flag) { if(!m_hCom){ return 0; } DWORD dwBytesRead, dwErrorFlags; ClearCommError(m_hCom, &dwErrorFlags, NULL); if(!ReadFile(m_hCom, pBuf, ReadByte, &dwBytesRead, &m_OverlappedRead)){ if(GetLastError() == ERROR_IO_PENDING){ DWORD Result = WaitForSingleObject(m_OverlappedRead.hEvent, TimeOut); if(WAIT_TIMEOUT == Result || WAIT_OBJECT_0 == Result){ GetOverlappedResult(m_hCom, &m_OverlappedRead, &dwBytesRead, FALSE); } else { dwBytesRead = 0; } } else { dwBytesRead = 0; } } DWORD dwFlags = PURGE_RXABORT; if(dwBytesRead == 0 || Flag){ dwFlags |= PURGE_RXCLEAR; //清除接收缓存区 } PurgeComm(m_hCom, dwFlags); return (int)dwBytesRead; } int CCom::Read(BYTE *pBuf, DWORD ReadByte, DWORD TimeOut) { return ReadEX(pBuf, ReadByte, TimeOut, FALSE); } void CCom::Close() { if(m_hCom) { CloseHandle(m_hCom); //handle to object to close } if(m_OverlappedRead.hEvent) { CloseHandle(m_OverlappedRead.hEvent); } if(m_OverlappedWrite.hEvent){ CloseHandle(m_OverlappedWrite.hEvent); } m_hCom = NULL; m_OverlappedRead.hEvent = NULL; m_OverlappedWrite.hEvent = NULL; } void CCom::StratCounter() { Cnter = GetTickCount(); } DWORD CCom::GetCounter() { return GetTickCount() - Cnter; }