/* ** FILENAME CSerialPort.h ** ** PURPOSE This class can read, write and watch one serial port. ** It sends messages to its owner when something happends on the port ** The class creates a thread for reading and writing so the main ** program is not blocked. ** ** CREATION DATE 15-09-1997 ** LAST MODIFICATION 12-11-1997 ** ** AUTHOR Remon Spekreijse ** ** ************************************************************************************ ** author: mrlong date:2007-12-25 ** ** 改进 ** 1) 增加ClosePort ** 2) 增加 writetoProt() 两个方法 ** 3) 增加 SendData 与 RecvData 方法 ************************************************************************************** *************************************************************************************** ** author：liquanhai date:2011-11-04 ** 改进 ** 1）增加 ClosePort中交出控制权，防止死锁问题 ************************************************************************************** *************************************************************************************** ** author：wanglei date:2012-06-12 ** 改进 ** 1）将InitPort中 ** assert(portnr > 0 && portnr < 5); ** 改为 ** assert(portnr > 0 && portnr < 255); ** 去掉串口号限制 ** */ #ifndef __SERIALPORT_H__ #define __SERIALPORT_H__ #define WM_COMM_BREAK_DETECTED WM_USER+1 // A break was detected on input. #define WM_COMM_CTS_DETECTED WM_USER+2 // The CTS (clear-to-send) signal changed state. #define WM_COMM_DSR_DETECTED WM_USER+3 // The DSR (data-set-ready) signal changed state. #define WM_COMM_ERR_DETECTED WM_USER+4 // A line-status error occurred. Line-status errors are CE_FRAME, CE_OVERRUN, and CE_RXPARITY. #define WM_COMM_RING_DETECTED WM_USER+5 // A ring indicator was detected. #define WM_COMM_RLSD_DETECTED WM_USER+6 // The RLSD (receive-line-signal-detect) signal changed state. #define WM_COMM_RXCHAR WM_USER+7 // A character was received and placed in the input buffer. #define WM_COMM_RXFLAG_DETECTED WM_USER+8 // The event character was received and placed in the input buffer. #define WM_COMM_TXEMPTY_DETECTED WM_USER+9 // The last character in the output buffer was sent. class CSerialPort { public: // contruction and destruction CSerialPort(); virtual ~CSerialPort(); // port initialisation BOOL InitPort(CWnd* pPortOwner, UINT portnr = 1, UINT baud = 19200, char parity = 'N', UINT databits = 8, UINT stopsbits = 1, DWORD dwCommEvents = EV_RXCHAR | EV_CTS, UINT nBufferSize = 512, DWORD ReadIntervalTimeout = 1000, DWORD ReadTotalTimeoutMultiplier = 1000, DWORD ReadTotalTimeoutConstant = 1000, DWORD WriteTotalTimeoutMultiplier = 1000, DWORD WriteTotalTimeoutConstant = 1000); // start/stop comm watching BOOL StartMonitoring(); BOOL RestartMonitoring(); BOOL StopMonitoring(); DWORD GetWriteBufferSize(); DWORD GetCommEvents(); DCB GetDCB(); void WriteToPort(char* string); void WriteToPort(char* string,int n); // add by mrlong 2007-12-25 void WriteToPort(LPCTSTR string); // add by mrlong 2007-12-25 void WriteToPort(BYTE* Buffer, int n);// add by mrlong void ClosePort(); // add by mrlong 2007-12-2 void SendData(LPCTSTR lpszData, const int nLength); //串口发送函数 by mrlong 2008-2-15 BOOL RecvData(LPTSTR lpszData, const int nSize); //串口接收函数 by mrlong 2008-2-15 protected: // protected memberfunctions void ProcessErrorMessage(char* ErrorText); static UINT CommThread(LPVOID pParam); static void ReceiveChar(CSerialPort* port, COMSTAT comstat); static void WriteChar(CSerialPort* port); // thread CWinThread* m_Thread; // synchronisation objects CRITICAL_SECTION m_csCommunicationSync; BOOL m_bThreadAlive; // handles HANDLE m_hShutdownEvent; //stop发生的事件 HANDLE m_hComm; // read HANDLE m_hWriteEvent; // write // Event array. // One element is used for each event. There are two event handles for each port. // A Write event and a receive character event which is located in the overlapped structure (m_ov.hEvent). // There is a general shutdown when the port is closed. HANDLE m_hEventArray[3]; // structures OVERLAPPED m_ov; COMMTIMEOUTS m_CommTimeouts; DCB m_dcb; // owner window CWnd* m_pOwner; // misc UINT m_nPortNr; //????? char* m_szWriteBuffer; DWORD m_dwCommEvents; DWORD m_nWriteBufferSize; int m_nWriteSize; //add by mrlong 2007-12-25 }; #endif __SERIALPORT_H__
/* ** FILENAME CSerialPort.cpp ** ** PURPOSE This class can read, write and watch one serial port. ** It sends messages to its owner when something happends on the port ** The class creates a thread for reading and writing so the main ** program is not blocked. ** ** CREATION DATE 15-09-1997 ** LAST MODIFICATION 12-11-1997 ** ** AUTHOR Remon Spekreijse ** ** */ #include "stdafx.h" #include "SerialPort.h" #include <assert.h> // // Constructor // CSerialPort::CSerialPort() { m_hComm = NULL; // initialize overlapped structure members to zero m_ov.Offset = 0; m_ov.OffsetHigh = 0; // create events m_ov.hEvent = NULL; m_hWriteEvent = NULL; m_hShutdownEvent = NULL; m_szWriteBuffer = NULL; m_bThreadAlive = FALSE; m_nWriteSize = 1; } // // Delete dynamic memory // CSerialPort::~CSerialPort() { do { SetEvent(m_hShutdownEvent); } while (m_bThreadAlive); if (m_hComm != NULL) { CloseHandle(m_hComm); m_hComm = NULL; } // Close Handles if(m_hShutdownEvent!=NULL) CloseHandle( m_hShutdownEvent); if(m_ov.hEvent!=NULL) CloseHandle( m_ov.hEvent ); if(m_hWriteEvent!=NULL) CloseHandle( m_hWriteEvent ); TRACE("Thread ended\n"); delete [] m_szWriteBuffer; } // // Initialize the port. This can be port 1 to 4. // // //parity: // n=none // e=even // o=odd // m=mark // s=space //data: // 5,6,7,8 //stop: // 1,1.5,2 // BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message) UINT portnr, UINT baud, // baudrate char parity, // parity UINT databits, // databits UINT stopbits, // stopbits DWORD dwCommEvents, // EV_RXCHAR, EV_CTS etc UINT writebuffersize,// size to the writebuffer DWORD ReadIntervalTimeout, DWORD ReadTotalTimeoutMultiplier, DWORD ReadTotalTimeoutConstant, DWORD WriteTotalTimeoutMultiplier, DWORD WriteTotalTimeoutConstant ) { //assert(portnr > 0 && portnr < 5);//Del by wl 20120612 assert(pPortOwner != NULL); // if the thread is alive: Kill if (m_bThreadAlive) { do { SetEvent(m_hShutdownEvent); } while (m_bThreadAlive); TRACE("Thread ended\n"); } // create events if (m_ov.hEvent != NULL) ResetEvent(m_ov.hEvent); else m_ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); if (m_hWriteEvent != NULL) ResetEvent(m_hWriteEvent); else m_hWriteEvent = CreateEvent(NULL, TRUE, FALSE, NULL); if (m_hShutdownEvent != NULL) ResetEvent(m_hShutdownEvent); else m_hShutdownEvent = CreateEvent(NULL, TRUE, FALSE, NULL); // initialize the event objects m_hEventArray[0] = m_hShutdownEvent; // highest priority m_hEventArray[1] = m_ov.hEvent; m_hEventArray[2] = m_hWriteEvent; // initialize critical section InitializeCriticalSection(&m_csCommunicationSync); // set buffersize for writing and save the owner m_pOwner = pPortOwner; if (m_szWriteBuffer != NULL) delete [] m_szWriteBuffer; m_szWriteBuffer = new char[writebuffersize]; m_nPortNr = portnr; m_nWriteBufferSize = writebuffersize; m_dwCommEvents = dwCommEvents; BOOL bResult = FALSE; char *szPort = new char[50]; char *szBaud = new char[50]; // now it critical! EnterCriticalSection(&m_csCommunicationSync); // if the port is already opened: close it if (m_hComm != NULL) { CloseHandle(m_hComm); m_hComm = NULL; } // prepare port strings sprintf(szPort, "COM%d", portnr); // stop is index 0 = 1 1=1.5 2=2 int mystop; int myparity; switch(stopbits) { case 0: mystop = ONESTOPBIT; break; case 1: mystop = ONE5STOPBITS; break; case 2: mystop = TWOSTOPBITS; break; } myparity = 0; switch(parity) { case 'N': myparity = 0; break; case 'E': myparity = 1; break; case 'O': myparity = 2; break; case 'M': myparity = 3; break; case 'S': myparity = 4; break; } sprintf(szBaud, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, mystop); // get a handle to the port m_hComm = CreateFile(szPort, // communication port string (COMX) GENERIC_READ | GENERIC_WRITE, // read/write types 0, // comm devices must be opened with exclusive access NULL, // no security attributes OPEN_EXISTING, // comm devices must use OPEN_EXISTING FILE_FLAG_OVERLAPPED, // Async I/O 0); // template must be 0 for comm devices if (m_hComm == INVALID_HANDLE_VALUE) { // port not found delete [] szPort; delete [] szBaud; return FALSE; } // set the timeout values m_CommTimeouts.ReadIntervalTimeout = ReadIntervalTimeout * 1000; m_CommTimeouts.ReadTotalTimeoutMultiplier = ReadTotalTimeoutMultiplier * 1000; m_CommTimeouts.ReadTotalTimeoutConstant = ReadTotalTimeoutConstant * 1000; m_CommTimeouts.WriteTotalTimeoutMultiplier = WriteTotalTimeoutMultiplier * 1000; m_CommTimeouts.WriteTotalTimeoutConstant = WriteTotalTimeoutConstant * 1000; // configure if (SetCommTimeouts(m_hComm, &m_CommTimeouts)) { if (SetCommMask(m_hComm, dwCommEvents)) { if (GetCommState(m_hComm, &m_dcb)) { m_dcb.EvtChar = 'q'; m_dcb.fRtsControl = RTS_CONTROL_ENABLE; // set RTS bit high! m_dcb.BaudRate = baud; // add by mrlong m_dcb.Parity = myparity; m_dcb.ByteSize = databits; m_dcb.StopBits = mystop; if (BuildCommDCB(szBaud, &m_dcb)) { if (SetCommState(m_hComm, &m_dcb)) ; // normal operation... continue else ProcessErrorMessage("SetCommState()"); } else ProcessErrorMessage("BuildCommDCB()"); } else ProcessErrorMessage("GetCommState()"); } else ProcessErrorMessage("SetCommMask()"); } else ProcessErrorMessage("SetCommTimeouts()"); delete [] szPort; delete [] szBaud; // flush the port PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); // release critical section LeaveCriticalSection(&m_csCommunicationSync); TRACE("Initialisation for communicationport %d completed.\nUse Startmonitor to communicate.\n", portnr); return TRUE; } // // The CommThread Function. // UINT CSerialPort::CommThread(LPVOID pParam) { // Cast the void pointer passed to the thread back to // a pointer of CSerialPort class CSerialPort *port = (CSerialPort*)pParam; // Set the status variable in the dialog class to // TRUE to indicate the thread is running. port->m_bThreadAlive = TRUE; // Misc. variables DWORD BytesTransfered = 0; DWORD Event = 0; DWORD CommEvent = 0; DWORD dwError = 0; COMSTAT comstat; BOOL bResult = TRUE; // Clear comm buffers at startup if (port->m_hComm) // check if the port is opened PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); // begin forever loop. This loop will run as long as the thread is alive. for (;;) { // Make a call to WaitCommEvent(). This call will return immediatly // because our port was created as an async port (FILE_FLAG_OVERLAPPED // and an m_OverlappedStructerlapped structure specified). This call will cause the // m_OverlappedStructerlapped element m_OverlappedStruct.hEvent, which is part of the m_hEventArray to // be placed in a non-signeled state if there are no bytes available to be read, // or to a signeled state if there are bytes available. If this event handle // is set to the non-signeled state, it will be set to signeled when a // character arrives at the port. // we do this for each port! bResult = WaitCommEvent(port->m_hComm, &Event, &port->m_ov); if (!bResult) { // If WaitCommEvent() returns FALSE, process the last error to determin // the reason.. switch (dwError = GetLastError()) { case ERROR_IO_PENDING: { // This is a normal return value if there are no bytes // to read at the port. // Do nothing and continue break; } case 87: { // Under Windows NT, this value is returned for some reason. // I have not investigated why, but it is also a valid reply // Also do nothing and continue. break; } default: { // All other error codes indicate a serious error has // occured. Process this error. port->ProcessErrorMessage("WaitCommEvent()"); break; } } } else { // If WaitCommEvent() returns TRUE, check to be sure there are // actually bytes in the buffer to read. // // If you are reading more than one byte at a time from the buffer // (which this program does not do) you will have the situation occur // where the first byte to arrive will cause the WaitForMultipleObjects() // function to stop waiting. The WaitForMultipleObjects() function // resets the event handle in m_OverlappedStruct.hEvent to the non-signelead state // as it returns. // // If in the time between the reset of this event and the call to // ReadFile() more bytes arrive, the m_OverlappedStruct.hEvent handle will be set again // to the signeled state. When the call to ReadFile() occurs, it will // read all of the bytes from the buffer, and the program will // loop back around to WaitCommEvent(). // // At this point you will be in the situation where m_OverlappedStruct.hEvent is set, // but there are no bytes available to read. If you proceed and call // ReadFile(), it will return immediatly due to the async port setup, but // GetOverlappedResults() will not return until the next character arrives. // // It is not desirable for the GetOverlappedResults() function to be in // this state. The thread shutdown event (event 0) and the WriteFile() // event (Event2) will not work if the thread is blocked by GetOverlappedResults(). // // The solution to this is to check the buffer with a call to ClearCommError(). // This call will reset the event handle, and if there are no bytes to read // we can loop back through WaitCommEvent() again, then proceed. // If there are really bytes to read, do nothing and proceed. bResult = ClearCommError(port->m_hComm, &dwError, &comstat); if (comstat.cbInQue == 0) continue; } // end if bResult // Main wait function. This function will normally block the thread // until one of nine events occur that require action. Event = WaitForMultipleObjects(3, port->m_hEventArray, FALSE, INFINITE); switch (Event) { case 0: { // Shutdown event. This is event zero so it will be // the higest priority and be serviced first. port->m_bThreadAlive = FALSE; // Kill this thread. break is not needed, but makes me feel better. AfxEndThread(100); break; } case 1: // read event { GetCommMask(port->m_hComm, &CommEvent); if (CommEvent & EV_RXCHAR) //接收到字符，并置于输入缓冲区中 ReceiveChar(port, comstat); if (CommEvent & EV_CTS) //CTS信号状态发生变化 ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_CTS_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); if (CommEvent & EV_RXFLAG) //接收到事件字符，并置于输入缓冲区中 ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RXFLAG_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); if (CommEvent & EV_BREAK) //输入中发生中断 ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_BREAK_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); if (CommEvent & EV_ERR) //发生线路状态错误，线路状态错误包括CE_FRAME,CE_OVERRUN和CE_RXPARITY ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_ERR_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); if (CommEvent & EV_RING) //检测到振铃指示 ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RING_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); break; } case 2: // write event { // Write character event from port WriteChar(port); break; } } // end switch } // close forever loop return 0; } // // start comm watching // BOOL CSerialPort::StartMonitoring() { if (!(m_Thread = AfxBeginThread(CommThread, this))) return FALSE; TRACE("Thread started\n"); return TRUE; } // // Restart the comm thread // BOOL CSerialPort::RestartMonitoring() { TRACE("Thread resumed\n"); m_Thread->ResumeThread(); return TRUE; } // // Suspend the comm thread // BOOL CSerialPort::StopMonitoring() { TRACE("Thread suspended\n"); m_Thread->SuspendThread(); return TRUE; } // // If there is a error, give the right message // void CSerialPort::ProcessErrorMessage(char* ErrorText) { char *Temp = new char[200]; LPVOID lpMsgBuf; FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language (LPTSTR) &lpMsgBuf, 0, NULL ); sprintf(Temp, "WARNING: %s Failed with the following error: \n%s\nPort: %d\n", (char*)ErrorText, lpMsgBuf, m_nPortNr); MessageBox(NULL, Temp, "Application Error", MB_ICONSTOP); LocalFree(lpMsgBuf); delete[] Temp; } // // Write a character. // void CSerialPort::WriteChar(CSerialPort* port) { BOOL bWrite = TRUE; BOOL bResult = TRUE; DWORD BytesSent = 0; DWORD SendLen = port->m_nWriteSize; ResetEvent(port->m_hWriteEvent); // Gain ownership of the critical section EnterCriticalSection(&port->m_csCommunicationSync); if (bWrite) { // Initailize variables port->m_ov.Offset = 0; port->m_ov.OffsetHigh = 0; // Clear buffer PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); bResult = WriteFile(port->m_hComm, // Handle to COMM Port port->m_szWriteBuffer, // Pointer to message buffer in calling finction SendLen, // add by mrlong //strlen((char*)port->m_szWriteBuffer), // Length of message to send &BytesSent, // Where to store the number of bytes sent &port->m_ov); // Overlapped structure // deal with any error codes if (!bResult) { DWORD dwError = GetLastError(); switch (dwError) { case ERROR_IO_PENDING: { // continue to GetOverlappedResults() BytesSent = 0; bWrite = FALSE; break; } default: { // all other error codes port->ProcessErrorMessage("WriteFile()"); } } } else { LeaveCriticalSection(&port->m_csCommunicationSync); } } // end if(bWrite) if (!bWrite) { bWrite = TRUE; bResult = GetOverlappedResult(port->m_hComm, // Handle to COMM port &port->m_ov, // Overlapped structure &BytesSent, // Stores number of bytes sent TRUE); // Wait flag LeaveCriticalSection(&port->m_csCommunicationSync); // deal with the error code if (!bResult) { port->ProcessErrorMessage("GetOverlappedResults() in WriteFile()"); } } // end if (!bWrite) // Verify that the data size send equals what we tried to send if (BytesSent != SendLen /*strlen((char*)port->m_szWriteBuffer)*/) // add by { TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n", BytesSent, strlen((char*)port->m_szWriteBuffer)); } } // // Character received. Inform the owner // void CSerialPort::ReceiveChar(CSerialPort* port, COMSTAT comstat) { BOOL bRead = TRUE; BOOL bResult = TRUE; DWORD dwError = 0; DWORD BytesRead = 0; unsigned char RXBuff; for (;;) { //add by liquanhai 防止死锁 if(WaitForSingleObject(port->m_hShutdownEvent,0)==WAIT_OBJECT_0) return; // Gain ownership of the comm port critical section. // This process guarantees no other part of this program // is using the port object. EnterCriticalSection(&port->m_csCommunicationSync); // ClearCommError() will update the COMSTAT structure and // clear any other errors. bResult = ClearCommError(port->m_hComm, &dwError, &comstat); LeaveCriticalSection(&port->m_csCommunicationSync); // start forever loop. I use this type of loop because I // do not know at runtime how many loops this will have to // run. My solution is to start a forever loop and to // break out of it when I have processed all of the // data available. Be careful with this approach and // be sure your loop will exit. // My reasons for this are not as clear in this sample // as it is in my production code, but I have found this // solutiion to be the most efficient way to do this. if (comstat.cbInQue == 0) { // break out when all bytes have been read break; } EnterCriticalSection(&port->m_csCommunicationSync); if (bRead) { 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 (!bResult) { switch (dwError = GetLastError()) { case ERROR_IO_PENDING: { // asynchronous i/o is still in progress // Proceed on to GetOverlappedResults(); bRead = FALSE; break; } default: { // Another error has occured. Process this error. port->ProcessErrorMessage("ReadFile()"); break; } } } else { // ReadFile() returned complete. It is not necessary to call GetOverlappedResults() bRead = TRUE; } } // close if (bRead) if (!bRead) { bRead = TRUE; bResult = GetOverlappedResult(port->m_hComm, // Handle to COMM port &port->m_ov, // Overlapped structure &BytesRead, // Stores number of bytes read TRUE); // Wait flag // deal with the error code if (!bResult) { port->ProcessErrorMessage("GetOverlappedResults() in ReadFile()"); } } // close if (!bRead) LeaveCriticalSection(&port->m_csCommunicationSync); // notify parent that a byte was received ::SendMessage((port->m_pOwner)->m_hWnd, WM_COMM_RXCHAR, (WPARAM) RXBuff, (LPARAM) port->m_nPortNr); } // end forever loop } // // Write a string to the port // void CSerialPort::WriteToPort(char* string) { assert(m_hComm != 0); memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer)); strcpy(m_szWriteBuffer, string); m_nWriteSize=strlen(string); // add by mrlong // set event for write SetEvent(m_hWriteEvent); } // // Return the device control block // DCB CSerialPort::GetDCB() { return m_dcb; } // // Return the communication event masks // DWORD CSerialPort::GetCommEvents() { return m_dwCommEvents; } // // Return the output buffer size // DWORD CSerialPort::GetWriteBufferSize() { return m_nWriteBufferSize; } void CSerialPort::ClosePort() { MSG message; do { SetEvent(m_hShutdownEvent); if(::PeekMessage(&message,m_pOwner->m_hWnd,0,0,PM_REMOVE)) { ::TranslateMessage(&message); ::DispatchMessage(&message); } } while (m_bThreadAlive); // if the port is still opened: close it if (m_hComm != NULL) { CloseHandle(m_hComm); m_hComm = NULL; } // Close Handles if(m_hShutdownEvent!=NULL) ResetEvent(m_hShutdownEvent); if(m_ov.hEvent!=NULL) ResetEvent(m_ov.hEvent); if(m_hWriteEvent!=NULL) ResetEvent(m_hWriteEvent); //delete [] m_szWriteBuffer; } void CSerialPort::WriteToPort(char* string,int n) { assert(m_hComm != 0); memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer)); memcpy(m_szWriteBuffer, string, n); m_nWriteSize = n; // set event for write SetEvent(m_hWriteEvent); } void CSerialPort::WriteToPort(LPCTSTR string) { assert(m_hComm != 0); memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer)); strcpy(m_szWriteBuffer, string); m_nWriteSize=strlen(string); // set event for write SetEvent(m_hWriteEvent); } void CSerialPort::WriteToPort(BYTE* Buffer, int n) { assert(m_hComm != 0); memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer)); int i; for(i=0; i<n; i++) { m_szWriteBuffer[i] = Buffer[i]; } m_nWriteSize=n; // set event for write SetEvent(m_hWriteEvent); } void CSerialPort::SendData(LPCTSTR lpszData, const int nLength) { assert(m_hComm != 0); memset(m_szWriteBuffer, 0, nLength); strcpy(m_szWriteBuffer, lpszData); m_nWriteSize=nLength; // set event for write SetEvent(m_hWriteEvent); } BOOL CSerialPort::RecvData(LPTSTR lpszData, const int nSize) { // //接收数据 // assert(m_hComm!=0); memset(lpszData,0,nSize); DWORD mylen = 0; DWORD mylen2 = 0; while (mylen<nSize) { if(!ReadFile(m_hComm,lpszData,nSize,&mylen2,NULL)) return FALSE; mylen += mylen2; } return TRUE; }