SerialPort.h SerialPort.cpp
SerialPort.h
1 #ifndef __SERIALPORT_H__ 2 #define __SERIALPORT_H__ 3 4 #define WM_COMM_BREAK_DETECTED WM_USER+1 // A break was detected on input. 5 #define WM_COMM_CTS_DETECTED WM_USER+2 // The CTS (clear-to-send) signal changed state. 6 #define WM_COMM_DSR_DETECTED WM_USER+3 // The DSR (data-set-ready) signal changed state. 7 #define WM_COMM_ERR_DETECTED WM_USER+4 // A line-status error occurred. Line-status errors are CE_FRAME, CE_OVERRUN, and CE_RXPARITY. 8 #define WM_COMM_RING_DETECTED WM_USER+5 // A ring indicator was detected. 9 #define WM_COMM_RLSD_DETECTED WM_USER+6 // The RLSD (receive-line-signal-detect) signal changed state. 10 #define WM_COMM_RXCHAR WM_USER+7 // A character was received and placed in the input buffer. 11 #define WM_COMM_RXFLAG_DETECTED WM_USER+8 // The event character was received and placed in the input buffer. 12 #define WM_COMM_TXEMPTY_DETECTED WM_USER+9 // The last character in the output buffer was sent. 13 14 class CSerialPort 15 { 16 public: 17 // contruction and destruction 18 CSerialPort(); // 构造函数 19 virtual ~CSerialPort(); //析构函数虚拟化了，是为了不同端口对象被消灭的时候，可以进行不同的收尾工作 20 21 // port initialisation 22 BOOL InitPort(CWnd* pPortOwner, UINT portnr = 1, UINT baud = 19200, 23 char parity = 'N', UINT databits = 8, UINT stopsbits = 1, 24 DWORD dwCommEvents = EV_RXCHAR | EV_CTS, UINT nBufferSize = 512, 25 26 DWORD ReadIntervalTimeout = 1000, 27 DWORD ReadTotalTimeoutMultiplier = 1000, 28 DWORD ReadTotalTimeoutConstant = 1000, 29 DWORD WriteTotalTimeoutMultiplier = 1000, 30 DWORD WriteTotalTimeoutConstant = 1000); 31 32 // start/stop comm watching 33 BOOL StartMonitoring(); 34 BOOL RestartMonitoring(); 35 BOOL StopMonitoring(); 36 37 DWORD GetWriteBufferSize(); 38 DWORD GetCommEvents(); 39 DCB GetDCB(); 40 41 void WriteToPort(char* string); 42 void WriteToPort(char* string,int n); // add by mrlong 2007-12-25 43 void WriteToPort(LPCTSTR string); // add by mrlong 2007-12-25 44 void WriteToPort(BYTE* Buffer, int n);// add by mrlong 45 void ClosePort(); // add by mrlong 2007-12-2 46 47 void SendData(LPCTSTR lpszData, const int nLength); //串口发送函数 by mrlong 2008-2-15 48 BOOL RecvData(LPTSTR lpszData, const int nSize); //串口接收函数 by mrlong 2008-2-15 49 50 protected: 51 // protected memberfunctions 52 void ProcessErrorMessage(char* ErrorText); 53 static UINT CommThread(LPVOID pParam); 54 static void ReceiveChar(CSerialPort* port, COMSTAT comstat); 55 static void WriteChar(CSerialPort* port); 56 57 // thread 58 CWinThread* m_Thread; 59 60 // synchronisation objects 61 CRITICAL_SECTION m_csCommunicationSync; 62 BOOL m_bThreadAlive; 63 64 // handles 65 HANDLE m_hShutdownEvent; //stop发生的事件 66 HANDLE m_hComm; // read 67 HANDLE m_hWriteEvent; // write 68 69 // Event array. 70 // One element is used for each event. There are two event handles for each port. 71 // A Write event and a receive character event which is located in the overlapped structure (m_ov.hEvent). 72 // There is a general shutdown when the port is closed. 73 HANDLE m_hEventArray[3]; 74 75 // structures 76 OVERLAPPED m_ov; 77 COMMTIMEOUTS m_CommTimeouts; 78 DCB m_dcb; 79 80 // owner window 81 CWnd* m_pOwner; 82 83 // misc 84 UINT m_nPortNr; //????? 85 char* m_szWriteBuffer; 86 DWORD m_dwCommEvents; 87 DWORD m_nWriteBufferSize; 88 89 int m_nWriteSize; //add by mrlong 2007-12-25 90 }; 91 92 #endif __SERIALPORT_H__
SerialPort.cpp
1 #include "stdafx.h" 2 #include "SerialPort.h" 3 4 #include <assert.h> 5 6 // 7 // Constructor 8 // 9 CSerialPort::CSerialPort() 10 { 11 m_hComm = NULL; 12 13 // initialize overlapped structure members to zero 14 m_ov.Offset = 0; 15 m_ov.OffsetHigh = 0; 16 17 // create events 18 m_ov.hEvent = NULL; 19 m_hWriteEvent = NULL; 20 m_hShutdownEvent = NULL; 21 22 m_szWriteBuffer = NULL; 23 24 m_bThreadAlive = FALSE; 25 m_nWriteSize = 1; 26 } 27 28 // 29 // Delete dynamic memory 30 // 31 CSerialPort::~CSerialPort() 32 { 33 do 34 { 35 SetEvent(m_hShutdownEvent); 36 } while (m_bThreadAlive); 37 38 if (m_hComm != NULL) 39 { 40 CloseHandle(m_hComm); 41 m_hComm = NULL; 42 } 43 // Close Handles 44 if(m_hShutdownEvent!=NULL) 45 CloseHandle( m_hShutdownEvent); 46 if(m_ov.hEvent!=NULL) 47 CloseHandle( m_ov.hEvent ); 48 if(m_hWriteEvent!=NULL) 49 CloseHandle( m_hWriteEvent ); 50 51 TRACE("Thread ended\n"); 52 53 delete [] m_szWriteBuffer; 54 } 55 56 // 57 // Initialize the port. This can be port 1 to 4. 58 // 59 // 60 //parity: 61 // n=none 62 // e=even 63 // o=odd 64 // m=mark 65 // s=space 66 //data: 67 // 5,6,7,8 68 //stop: 69 // 1,1.5,2 70 // 71 BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message) 72 UINT portnr, 73 UINT baud, // baudrate 74 char parity, // parity 75 UINT databits, // databits 76 UINT stopbits, // stopbits 77 DWORD dwCommEvents, // EV_RXCHAR, EV_CTS etc 78 UINT writebuffersize,// size to the writebuffer 79 80 DWORD ReadIntervalTimeout, 81 DWORD ReadTotalTimeoutMultiplier, 82 DWORD ReadTotalTimeoutConstant, 83 DWORD WriteTotalTimeoutMultiplier, 84 DWORD WriteTotalTimeoutConstant ) 85 86 { 87 //assert(portnr > 0 && portnr < 5);//Del by wl 20120612 88 assert(pPortOwner != NULL); 89 90 // if the thread is alive: Kill 91 if (m_bThreadAlive) 92 { 93 do 94 { 95 SetEvent(m_hShutdownEvent); 96 } while (m_bThreadAlive); 97 TRACE("Thread ended\n"); 98 } 99 100 // create events 101 if (m_ov.hEvent != NULL) 102 ResetEvent(m_ov.hEvent); 103 else 104 m_ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); 105 106 if (m_hWriteEvent != NULL) 107 ResetEvent(m_hWriteEvent); 108 else 109 m_hWriteEvent = CreateEvent(NULL, TRUE, FALSE, NULL); 110 111 if (m_hShutdownEvent != NULL) 112 ResetEvent(m_hShutdownEvent); 113 else 114 m_hShutdownEvent = CreateEvent(NULL, TRUE, FALSE, NULL); 115 116 // initialize the event objects 117 m_hEventArray[0] = m_hShutdownEvent; // highest priority 118 m_hEventArray[1] = m_ov.hEvent; 119 m_hEventArray[2] = m_hWriteEvent; 120 121 // initialize critical section 122 InitializeCriticalSection(&m_csCommunicationSync); 123 124 // set buffersize for writing and save the owner 125 m_pOwner = pPortOwner; 126 127 if (m_szWriteBuffer != NULL) 128 delete [] m_szWriteBuffer; 129 m_szWriteBuffer = new char[writebuffersize]; 130 131 m_nPortNr = portnr; 132 133 m_nWriteBufferSize = writebuffersize; 134 m_dwCommEvents = dwCommEvents; 135 136 BOOL bResult = FALSE; 137 char *szPort = new char[50]; 138 char *szBaud = new char[50]; 139 140 // now it critical! 141 EnterCriticalSection(&m_csCommunicationSync); 142 143 // if the port is already opened: close it 144 if (m_hComm != NULL) 145 { 146 CloseHandle(m_hComm); 147 m_hComm = NULL; 148 } 149 150 // prepare port strings 151 sprintf(szPort, "COM%d", portnr); 152 // stop is index 0 = 1 1=1.5 2=2 153 int mystop; 154 int myparity; 155 switch(stopbits) 156 { 157 case 0: 158 mystop = ONESTOPBIT; 159 break; 160 case 1: 161 mystop = ONE5STOPBITS; 162 break; 163 case 2: 164 mystop = TWOSTOPBITS; 165 break; 166 } 167 myparity = 0; 168 switch(parity) 169 { 170 case 'N': 171 myparity = 0; 172 break; 173 case 'E': 174 myparity = 1; 175 break; 176 case 'O': 177 myparity = 2; 178 break; 179 case 'M': 180 myparity = 3; 181 break; 182 case 'S': 183 myparity = 4; 184 break; 185 } 186 sprintf(szBaud, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, mystop); 187 188 // get a handle to the port 189 m_hComm = CreateFile(szPort, // communication port string (COMX) 190 GENERIC_READ | GENERIC_WRITE, // read/write types 191 0, // comm devices must be opened with exclusive access 192 NULL, // no security attributes 193 OPEN_EXISTING, // comm devices must use OPEN_EXISTING 194 FILE_FLAG_OVERLAPPED, // Async I/O 195 0); // template must be 0 for comm devices 196 197 if (m_hComm == INVALID_HANDLE_VALUE) 198 { 199 // port not found 200 delete [] szPort; 201 delete [] szBaud; 202 203 return FALSE; 204 } 205 206 // set the timeout values 207 m_CommTimeouts.ReadIntervalTimeout = ReadIntervalTimeout * 1000; 208 m_CommTimeouts.ReadTotalTimeoutMultiplier = ReadTotalTimeoutMultiplier * 1000; 209 m_CommTimeouts.ReadTotalTimeoutConstant = ReadTotalTimeoutConstant * 1000; 210 m_CommTimeouts.WriteTotalTimeoutMultiplier = WriteTotalTimeoutMultiplier * 1000; 211 m_CommTimeouts.WriteTotalTimeoutConstant = WriteTotalTimeoutConstant * 1000; 212 213 // configure 214 if (SetCommTimeouts(m_hComm, &m_CommTimeouts)) 215 { 216 if (SetCommMask(m_hComm, dwCommEvents)) 217 { 218 if (GetCommState(m_hComm, &m_dcb)) 219 { 220 m_dcb.EvtChar = 'q'; 221 m_dcb.fRtsControl = RTS_CONTROL_ENABLE; // set RTS bit high! 222 m_dcb.BaudRate = baud; // add by mrlong 223 m_dcb.Parity = myparity; 224 m_dcb.ByteSize = databits; 225 m_dcb.StopBits = mystop; 226 227 if (BuildCommDCB(szBaud, &m_dcb)) 228 { 229 if (SetCommState(m_hComm, &m_dcb)) 230 ; // normal operation... continue 231 else 232 ProcessErrorMessage("SetCommState()"); 233 } 234 else 235 ProcessErrorMessage("BuildCommDCB()"); 236 } 237 else 238 ProcessErrorMessage("GetCommState()"); 239 } 240 else 241 ProcessErrorMessage("SetCommMask()"); 242 } 243 else 244 ProcessErrorMessage("SetCommTimeouts()"); 245 246 delete [] szPort; 247 delete [] szBaud; 248 249 // flush the port 250 PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); 251 252 // release critical section 253 LeaveCriticalSection(&m_csCommunicationSync); 254 255 TRACE("Initialisation for communicationport %d completed.\nUse Startmonitor to communicate.\n", portnr); 256 257 return TRUE; 258 } 259 260 // 261 // The CommThread Function. 262 // 263 UINT CSerialPort::CommThread(LPVOID pParam) 264 { 265 // Cast the void pointer passed to the thread back to 266 // a pointer of CSerialPort class 267 CSerialPort *port = (CSerialPort*)pParam; 268 269 // Set the status variable in the dialog class to 270 // TRUE to indicate the thread is running. 271 port->m_bThreadAlive = TRUE; 272 273 // Misc. variables 274 DWORD BytesTransfered = 0; 275 DWORD Event = 0; 276 DWORD CommEvent = 0; 277 DWORD dwError = 0; 278 COMSTAT comstat; 279 BOOL bResult = TRUE; 280 // Clear comm buffers at startup 281 if (port->m_hComm) // check if the port is opened 282 PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); 283 284 // begin forever loop. This loop will run as long as the thread is alive. 285 for (;;) 286 { 287 288 // Make a call to WaitCommEvent(). This call will return immediatly 289 // because our port was created as an async port (FILE_FLAG_OVERLAPPED 290 // and an m_OverlappedStructerlapped structure specified). This call will cause the 291 // m_OverlappedStructerlapped element m_OverlappedStruct.hEvent, which is part of the m_hEventArray to 292 // be placed in a non-signeled state if there are no bytes available to be read, 293 // or to a signeled state if there are bytes available. If this event handle 294 // is set to the non-signeled state, it will be set to signeled when a 295 // character arrives at the port. 296 297 // we do this for each port! 298 299 bResult = WaitCommEvent(port->m_hComm, &Event, &port->m_ov); 300 301 if (!bResult) 302 { 303 // If WaitCommEvent() returns FALSE, process the last error to determin 304 // the reason.. 305 switch (dwError = GetLastError()) 306 { 307 case ERROR_IO_PENDING: 308 { 309 // This is a normal return value if there are no bytes 310 // to read at the port. 311 // Do nothing and continue 312 break; 313 } 314 case 87: 315 { 316 // Under Windows NT, this value is returned for some reason. 317 // I have not investigated why, but it is also a valid reply 318 // Also do nothing and continue. 319 break; 320 } 321 default: 322 { 323 // All other error codes indicate a serious error has 324 // occured. Process this error. 325 port->ProcessErrorMessage("WaitCommEvent()"); 326 break; 327 } 328 } 329 } 330 else 331 { 332 // If WaitCommEvent() returns TRUE, check to be sure there are 333 // actually bytes in the buffer to read. 334 // 335 // If you are reading more than one byte at a time from the buffer 336 // (which this program does not do) you will have the situation occur 337 // where the first byte to arrive will cause the WaitForMultipleObjects() 338 // function to stop waiting. The WaitForMultipleObjects() function 339 // resets the event handle in m_OverlappedStruct.hEvent to the non-signelead state 340 // as it returns. 341 // 342 // If in the time between the reset of this event and the call to 343 // ReadFile() more bytes arrive, the m_OverlappedStruct.hEvent handle will be set again 344 // to the signeled state. When the call to ReadFile() occurs, it will 345 // read all of the bytes from the buffer, and the program will 346 // loop back around to WaitCommEvent(). 347 // 348 // At this point you will be in the situation where m_OverlappedStruct.hEvent is set, 349 // but there are no bytes available to read. If you proceed and call 350 // ReadFile(), it will return immediatly due to the async port setup, but 351 // GetOverlappedResults() will not return until the next character arrives. 352 // 353 // It is not desirable for the GetOverlappedResults() function to be in 354 // this state. The thread shutdown event (event 0) and the WriteFile() 355 // event (Event2) will not work if the thread is blocked by GetOverlappedResults(). 356 // 357 // The solution to this is to check the buffer with a call to ClearCommError(). 358 // This call will reset the event handle, and if there are no bytes to read 359 // we can loop back through WaitCommEvent() again, then proceed. 360 // If there are really bytes to read, do nothing and proceed. 361 362 bResult = ClearCommError(port->m_hComm, &dwError, &comstat); 363 364 if (comstat.cbInQue == 0) 365 continue; 366 } // end if bResult 367 368 // Main wait function. This function will normally block the thread 369 // until one of nine events occur that require action. 370 Event = WaitForMultipleObjects(3, port->m_hEventArray, FALSE, INFINITE); 371 372 switch (Event) 373 { 374 case 0: 375 { 376 // Shutdown event. This is event zero so it will be 377 // the higest priority and be serviced first. 378 379 port->m_bThreadAlive = FALSE; 380 381 // Kill this thread. break is not needed, but makes me feel better. 382 AfxEndThread(100); 383 break; 384 } 385 case 1: // read event 386 { 387 GetCommMask(port->m_hComm, &CommEvent); 388 memset(&comstat, 0, sizeof(COMSTAT)); 389 if (CommEvent & EV_RXCHAR) //接收到字符，并置于输入缓冲区中 390 ReceiveChar(port, comstat); 391 392 if (CommEvent & EV_CTS) //CTS信号状态发生变化 393 ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_CTS_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); 394 if (CommEvent & EV_RXFLAG) //接收到事件字符，并置于输入缓冲区中 395 ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RXFLAG_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); 396 if (CommEvent & EV_BREAK) //输入中发生中断 397 ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_BREAK_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); 398 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 399 ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_ERR_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); 400 if (CommEvent & EV_RING) //检测到振铃指示 401 ::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RING_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr); 402 403 break; 404 } 405 case 2: // write event 406 { 407 // Write character event from port 408 WriteChar(port); 409 break; 410 } 411 412 } // end switch 413 414 } // close forever loop 415 416 return 0; 417 } 418 // 419 // start comm watching 420 // 421 BOOL CSerialPort::StartMonitoring() 422 { 423 if (!(m_Thread = AfxBeginThread(CommThread, this))) 424 return FALSE; 425 TRACE("Thread started\n"); 426 return TRUE; 427 } 428 // 429 // Restart the comm thread 430 // 431 BOOL CSerialPort::RestartMonitoring() 432 { 433 TRACE("Thread resumed\n"); 434 m_Thread->ResumeThread(); 435 return TRUE; 436 } 437 438 439 // 440 // Suspend the comm thread 441 // 442 BOOL CSerialPort::StopMonitoring() 443 { 444 TRACE("Thread suspended\n"); 445 m_Thread->SuspendThread(); 446 return TRUE; 447 } 448 449 450 // 451 // If there is a error, give the right message 452 // 453 void CSerialPort::ProcessErrorMessage(char* ErrorText) 454 { 455 char *Temp = new char[200]; 456 457 LPVOID lpMsgBuf; 458 459 FormatMessage( 460 FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, 461 NULL, 462 GetLastError(), 463 MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language 464 (LPTSTR) &lpMsgBuf, 465 0, 466 NULL 467 ); 468 469 sprintf(Temp, "WARNING: %s Failed with the following error: \n%s\nPort: %d\n", (char*)ErrorText, lpMsgBuf, m_nPortNr); 470 MessageBox(NULL, Temp, "Application Error", MB_ICONSTOP); 471 472 LocalFree(lpMsgBuf); 473 delete[] Temp; 474 } 475 476 // 477 // Write a character. 478 // 479 void CSerialPort::WriteChar(CSerialPort* port) 480 { 481 BOOL bWrite = TRUE; 482 BOOL bResult = TRUE; 483 484 DWORD BytesSent = 0; 485 DWORD SendLen = port->m_nWriteSize; 486 ResetEvent(port->m_hWriteEvent); 487 488 489 // Gain ownership of the critical section 490 EnterCriticalSection(&port->m_csCommunicationSync); 491 492 if (bWrite) 493 { 494 // Initailize variables 495 port->m_ov.Offset = 0; 496 port->m_ov.OffsetHigh = 0; 497 498 // Clear buffer 499 PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); 500 501 bResult = WriteFile(port->m_hComm, // Handle to COMM Port 502 port->m_szWriteBuffer, // Pointer to message buffer in calling finction 503 SendLen, // add by mrlong 504 //strlen((char*)port->m_szWriteBuffer), // Length of message to send 505 &BytesSent, // Where to store the number of bytes sent 506 &port->m_ov); // Overlapped structure 507 508 // deal with any error codes 509 if (!bResult) 510 { 511 DWORD dwError = GetLastError(); 512 switch (dwError) 513 { 514 case ERROR_IO_PENDING: 515 { 516 // continue to GetOverlappedResults() 517 BytesSent = 0; 518 bWrite = FALSE; 519 break; 520 } 521 default: 522 { 523 // all other error codes 524 port->ProcessErrorMessage("WriteFile()"); 525 } 526 } 527 } 528 else 529 { 530 LeaveCriticalSection(&port->m_csCommunicationSync); 531 } 532 } // end if(bWrite) 533 534 if (!bWrite) 535 { 536 bWrite = TRUE; 537 538 bResult = GetOverlappedResult(port->m_hComm, // Handle to COMM port 539 &port->m_ov, // Overlapped structure 540 &BytesSent, // Stores number of bytes sent 541 TRUE); // Wait flag 542 543 LeaveCriticalSection(&port->m_csCommunicationSync); 544 545 // deal with the error code 546 if (!bResult) 547 { 548 port->ProcessErrorMessage("GetOverlappedResults() in WriteFile()"); 549 } 550 } // end if (!bWrite) 551 552 // Verify that the data size send equals what we tried to send 553 if (BytesSent != SendLen /*strlen((char*)port->m_szWriteBuffer)*/) // add by 554 { 555 TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n", BytesSent, strlen((char*)port->m_szWriteBuffer)); 556 } 557 } 558 559 // 560 // Character received. Inform the owner 561 // 562 void CSerialPort::ReceiveChar(CSerialPort* port, COMSTAT comstat) 563 { 564 BOOL bRead = TRUE; 565 BOOL bResult = TRUE; 566 DWORD dwError = 0; 567 DWORD BytesRead = 0; 568 unsigned char RXBuff; 569 570 for (;;) 571 { 572 //add by liquanhai 防止死锁 573 if(WaitForSingleObject(port->m_hShutdownEvent,0)==WAIT_OBJECT_0) 574 return; 575 576 // Gain ownership of the comm port critical section. 577 // This process guarantees no other part of this program 578 // is using the port object. 579 580 EnterCriticalSection(&port->m_csCommunicationSync); 581 582 // ClearCommError() will update the COMSTAT structure and 583 // clear any other errors. 584 585 bResult = ClearCommError(port->m_hComm, &dwError, &comstat); 586 587 LeaveCriticalSection(&port->m_csCommunicationSync); 588 589 if (comstat.cbInQue == 0) 590 { 591 // break out when all bytes have been read 592 break; 593 } 594 595 EnterCriticalSection(&port->m_csCommunicationSync); 596 597 if (bRead) 598 { 599 bResult = ReadFile(port->m_hComm, // Handle to COMM port 600 &RXBuff, // RX Buffer Pointer 601 1, // Read one byte 602 &BytesRead, // Stores number of bytes read 603 &port->m_ov); // pointer to the m_ov structure 604 // deal with the error code 605 if (!bResult) 606 { 607 switch (dwError = GetLastError()) 608 { 609 case ERROR_IO_PENDING: 610 { 611 // asynchronous i/o is still in progress 612 // Proceed on to GetOverlappedResults(); 613 bRead = FALSE; 614 break; 615 } 616 default: 617 { 618 // Another error has occured. Process this error. 619 port->ProcessErrorMessage("ReadFile()"); 620 break; 621 } 622 } 623 } 624 else 625 { 626 // ReadFile() returned complete. It is not necessary to call GetOverlappedResults() 627 bRead = TRUE; 628 } 629 } // close if (bRead) 630 631 if (!bRead) 632 { 633 bRead = TRUE; 634 bResult = GetOverlappedResult(port->m_hComm, // Handle to COMM port 635 &port->m_ov, // Overlapped structure 636 &BytesRead, // Stores number of bytes read 637 TRUE); // Wait flag 638 639 // deal with the error code 640 if (!bResult) 641 { 642 port->ProcessErrorMessage("GetOverlappedResults() in ReadFile()"); 643 } 644 } // close if (!bRead) 645 646 LeaveCriticalSection(&port->m_csCommunicationSync); 647 648 // notify parent that a byte was received 649 ::SendMessage((port->m_pOwner)->m_hWnd, WM_COMM_RXCHAR, (WPARAM) RXBuff, (LPARAM) port->m_nPortNr); 650 } // end forever loop 651 652 } 653 654 // 655 // Write a string to the port 656 // 657 void CSerialPort::WriteToPort(char* string) 658 { 659 assert(m_hComm != 0); 660 661 memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer)); 662 strcpy(m_szWriteBuffer, string); 663 m_nWriteSize=strlen(string); // add by mrlong 664 // set event for write 665 SetEvent(m_hWriteEvent); 666 } 667 668 // 669 // Return the device control block 670 // 671 DCB CSerialPort::GetDCB() 672 { 673 return m_dcb; 674 } 675 676 // 677 // Return the communication event masks 678 // 679 DWORD CSerialPort::GetCommEvents() 680 { 681 return m_dwCommEvents; 682 } 683 684 // 685 // Return the output buffer size 686 // 687 DWORD CSerialPort::GetWriteBufferSize() 688 { 689 return m_nWriteBufferSize; 690 } 691 692 void CSerialPort::ClosePort() 693 { 694 MSG message; 695 do 696 { 697 SetEvent(m_hShutdownEvent); 698 if(::PeekMessage(&message,m_pOwner->m_hWnd,0,0,PM_REMOVE)) 699 { 700 ::TranslateMessage(&message); 701 ::DispatchMessage(&message); 702 } 703 704 } while (m_bThreadAlive); 705 706 // if the port is still opened: close it 707 if (m_hComm != NULL) 708 { 709 CloseHandle(m_hComm); 710 m_hComm = NULL; 711 } 712 713 // Close Handles 714 if(m_hShutdownEvent!=NULL) 715 ResetEvent(m_hShutdownEvent); 716 if(m_ov.hEvent!=NULL) 717 ResetEvent(m_ov.hEvent); 718 if(m_hWriteEvent!=NULL) 719 ResetEvent(m_hWriteEvent); 720 721 //delete [] m_szWriteBuffer; 722 723 } 724 725 void CSerialPort::WriteToPort(char* string,int n) 726 { 727 assert(m_hComm != 0); 728 memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer)); 729 memcpy(m_szWriteBuffer, string, n); 730 m_nWriteSize = n; 731 732 // set event for write 733 SetEvent(m_hWriteEvent); 734 } 735 736 void CSerialPort::WriteToPort(LPCTSTR string) 737 { 738 assert(m_hComm != 0); 739 memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer)); 740 strcpy(m_szWriteBuffer, string); 741 m_nWriteSize=strlen(string); 742 // set event for write 743 SetEvent(m_hWriteEvent); 744 } 745 746 void CSerialPort::WriteToPort(BYTE* Buffer, int n) 747 { 748 assert(m_hComm != 0); 749 memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));//清零 750 int i; 751 for(i=0; i<n; i++) 752 { 753 m_szWriteBuffer[i] = Buffer[i];//读缓存 754 } 755 m_nWriteSize=n; 756 757 // set event for write 758 SetEvent(m_hWriteEvent);//SetEvent/ResetEvent分别将EVENT置为这两种状态分别是发信号与不发信号 759 } 760 761 762 void CSerialPort::SendData(LPCTSTR lpszData, const int nLength) 763 { 764 assert(m_hComm != 0); 765 memset(m_szWriteBuffer, 0, nLength); 766 strcpy(m_szWriteBuffer, lpszData); 767 m_nWriteSize=nLength; 768 // set event for write 769 SetEvent(m_hWriteEvent); 770 } 771 772 BOOL CSerialPort::RecvData(LPTSTR lpszData, const int nSize) 773 { 774 // 775 //接收数据 776 // 777 assert(m_hComm!=0); 778 memset(lpszData,0,nSize); 779 DWORD mylen = 0; 780 DWORD mylen2 = 0; 781 while (mylen<nSize) { 782 if(!ReadFile(m_hComm,lpszData,nSize,&mylen2,NULL)) 783 return FALSE; 784 mylen += mylen2; 785 786 787 } 788 789 return TRUE; 790 }
