网上这方面三方类多如牛毛，真不知道用哪个好，不过不管用哪个，一定要在严格检查完善后再使用，不然给以后通信埋下隐患，只会让以后的调试会更痛苦!

//////////////////////////////////////////////////////////////////////  //  // ComAccess.h: interface for the CComAccess class.  //  //////////////////////////////////////////////////////////////////////  #if !defined(AFX_COMACCESS_H__F15FFC6E_D059_4E57_97CD_A672C05FF9B7__INCLUDED_)  #define AFX_COMACCESS_H__F15FFC6E_D059_4E57_97CD_A672C05FF9B7__INCLUDED_  #if _MSC_VER > 1000  #pragma once  #endif // _MSC_VER > 1000  class CComAccess   {  private:      HANDLE      m_hCom; // Device handle       OVERLAPPED  m_ov;   // A structure that contains informations which are                          // used for asynchronous input and output operations      TCHAR       m_lpszErrorMessage[256];  public:      CComAccess();      CComAccess(LPCSTR lpszPortNum);      ~CComAccess();                                      // For more definitions see <winbase.h>      BOOL    Open(LPCSTR lpszPortNum = "com1",                   DWORD  dwBaudRate  = CBR_9600,                    BYTE   byParity    = NOPARITY,                   BYTE   byStopBits  = ONESTOPBIT,                   BYTE   byByteSize  = 8);      VOID    Close();      DWORD   WriteData(LPCVOID pdata, DWORD len);      DWORD   ReadData(LPVOID  pdest, DWORD len, DWORD dwMaxWait = 500);      LPSTR   GetErrorMessage(VOID) { return m_lpszErrorMessage; }  private:      VOID    ErrorToString(LPCSTR lpszMessage);      BOOL    IsNT(VOID);  };  #endif // !defined(AFX_COMACCESS_H__F15FFC6E_D059_4E57_97CD_A672C05FF9B7__INCLUDED_) 

//////////////////////////////////////////////////////////////////////  //  // ComAccess.cpp: implementation of the CComAccess class.  //  //////////////////////////////////////////////////////////////////////  #include "stdafx.h"  #include "ComAccess.h"  #ifdef _DEBUG  #undef THIS_FILE  static char THIS_FILE[]=__FILE__;  #define new DEBUG_NEW  #endif//////////////////////////////////////////////////////////////////////  // Construction/Destruction  //////////////////////////////////////////////////////////////////////  CComAccess::CComAccess(VOID)  {      m_hCom = 0;      m_lpszErrorMessage[0] = ‘/0‘;      ZeroMemory(&m_ov, sizeof(m_ov));  }  CComAccess::CComAccess(LPCSTR lpszPortNum)  {       CComAccess::CComAccess();      CComAccess::Open(lpszPortNum);   }  CComAccess::~CComAccess()  {      Close();  }  ////////////////////////////////////////////////////////////////////////////////////////  //   //  Function:      Open(LPCSTR lpszPortNum,  //                      DWORD  dwBaudRate,   //                      BYTE   byParity,  //                      BYTE   byStopBits,  //                      BYTE   byByteSize)  //  //  Return value:  BOOL TRUE or FALSE  //  BOOL CComAccess::Open(LPCSTR lpszPortNum,                        DWORD  dwBaudRate,                        BYTE   byParity,                       BYTE   byStopBits,                       BYTE   byByteSize)  {      DCB  dcb; // structure that defines the control setting for a serial communications device      BOOL bSuccess;      m_hCom = CreateFile(lpszPortNum,           // pointer to name of the file                          GENERIC_READ|GENERIC_WRITE, // access mode                          0,                     // comm devices must be opened w/exclusive-access                           NULL,                  // no security attributs                           OPEN_EXISTING,         // comm devices must use OPEN_EXISTING                           FILE_FLAG_OVERLAPPED,  // overlapped I/O                          NULL);                 // hTemplate must be NULL for comm devices       if ( m_hCom == INVALID_HANDLE_VALUE )       {          // handle the error          CComAccess::ErrorToString("Open(): CreateFile() failed, invalid handle value");          return FALSE;      }      //      // Omit the call to SetupComm to use the default queue sizes.      // Get the current configuration.      //      bSuccess = GetCommState(m_hCom, &dcb);      if ( ! bSuccess )       {          // Handle the error.          CComAccess::ErrorToString("Open(): GetCommState() failed");          CComAccess::Close();          return FALSE;      }      //      // Fill in the DCB: baud=9600, 8 data bits, no parity, 1 stop bit are default parameters      //      dcb.BaudRate = dwBaudRate;      dcb.ByteSize = byByteSize;      dcb.Parity   = byParity;      dcb.StopBits = byStopBits;      bSuccess = SetCommState(m_hCom, &dcb);      if ( ! bSuccess )       {          // Handle the error.           CComAccess::ErrorToString("Open(): SetCommState() failed");          CComAccess::Close();          return FALSE;      }      return TRUE;  }  ////////////////////////////////////////////////////////////////////////////////////////  //   //  Function:      Close(VOID)  //  //  Return value:  VOID  //  VOID CComAccess::Close()  {      if ( m_hCom > 0 )      {          CloseHandle(m_hCom);      }      m_hCom = 0;   }  ////////////////////////////////////////////////////////////////////////////////////////  //   //  Function:     WriteData(LPCVOID pdata,   //                          DWORD   len)  //  //  Return value:  DWORD -1 failed, above, num written bytes  //  DWORD CComAccess::WriteData(LPCVOID pdata,                              DWORD   len)  {      BOOL  bSuccess;      DWORD written = 0;      if ( len < 1 )          return(0);      // create event for overlapped I/O      m_ov.hEvent = CreateEvent(NULL,   // pointer to security attributes                                 FALSE,   // flag for manual-reset event                                 FALSE,  // flag for initial state                                 "");    // pointer to event-object name       if ( m_ov.hEvent == INVALID_HANDLE_VALUE )      {          // Handle the error.          CComAccess::ErrorToString("WriteData(): CreateEvent() failed");          return(-1);      }      bSuccess = WriteFile(m_hCom,   // handle to file to write to                             pdata,    // pointer to data to write to file                            len,      // number of bytes to write                            &written, // pointer to number of bytes written                            &m_ov);   // pointer to structure needed for overlapped I/O      if ( CComAccess::IsNT() )      {          bSuccess = GetOverlappedResult(m_hCom, &m_ov, &written, TRUE);          if ( ! bSuccess )          {              // Handle the error.              CloseHandle(m_ov.hEvent);              CComAccess::ErrorToString("WriteData(): GetOverlappedResult() failed");              return(-1);          }      }      else      if ( len != written )      {          // Handle the error.          CloseHandle(m_ov.hEvent);          CComAccess::ErrorToString("WriteData(): WriteFile() failed");          return(-1);      }      CloseHandle(m_ov.hEvent);      return written;  }  ////////////////////////////////////////////////////////////////////////////////////////  //   //  Function:      ReadData(LPVOID pdest,   //                          DWORD  len,   //                          DWORD  dwMaxWait)  //  //  Return value:  DWORD -1 failed, above, num read bytes         //  DWORD CComAccess::ReadData(LPVOID pdest,                             DWORD  len,                             DWORD  dwMaxWait)  {      BOOL  bSuccess;      DWORD result = 0,            read   = 0, // num read bytes            mask   = 0; // a 32-bit variable that receives a mask                         // indicating the type of event that occurred      if ( len < 1 ) return(0);      // create event for overlapped I/O      m_ov.hEvent = CreateEvent(NULL,   // pointer to security attributes                                 FALSE,   // flag for manual-reset event                                 FALSE,  // flag for initial state                                 "");    // pointer to event-object name       if ( m_ov.hEvent == INVALID_HANDLE_VALUE )      {          // Handle the error.          CComAccess::ErrorToString("ReadData(): CreateEvent() failed");          return(-1);      }      // Specify here the event to be enabled      bSuccess = SetCommMask(m_hCom, EV_RXCHAR);      if ( ! bSuccess )      {          // Handle the error.          CloseHandle(m_ov.hEvent);          CComAccess::ErrorToString("ReadData(): SetCommMask() failed");          return(-1);      }      // WaitForSingleObject      bSuccess = WaitCommEvent(m_hCom, &mask, &m_ov);      if ( ! bSuccess )      {          int err = GetLastError();          if ( err == ERROR_IO_PENDING)          {              result = WaitForSingleObject(m_ov.hEvent, dwMaxWait);  //wait dwMaxWait                                                  // milli seconds before returning              if ( result == WAIT_FAILED )              {                  // Handle the error.                  CloseHandle(m_ov.hEvent);                  CComAccess::ErrorToString("ReadData(): WaitForSingleObject() failed");                  return(-1);              }          }      }      // The specified event occured?      if ( mask & EV_RXCHAR)       {          bSuccess = ReadFile(m_hCom, // handle of file to read                               pdest,  // address of buffer that receives data                               len,    // number of bytes to read                               &read,  // address of number of bytes read                               &m_ov); // address of structure for data           if ( CComAccess::IsNT() )          {              bSuccess = GetOverlappedResult(m_hCom, &m_ov, &read, TRUE);              if ( ! bSuccess )              {                  // Handle the error.                  CloseHandle(m_ov.hEvent);                  CComAccess::ErrorToString("WriteData(): GetOverlappedResult() failed");                  return(-1);              }          }          else          if ( ! bSuccess )          {              // Handle the error.              CloseHandle(m_ov.hEvent);              CComAccess::ErrorToString("ReadData(): ReadFile() failed");              return(-1);          }      }      else      {          // Handle the error.          CloseHandle(m_ov.hEvent);          wsprintf(m_lpszErrorMessage, "Error ReadData(): No EV_RXCHAR occured/n");          return(-1);      }      CloseHandle(m_ov.hEvent);      return read;  }  ////////////////////////////////////////////////////////////////////////////////////////  //   //  Function:      ErrorToString(LPCSTR lpszMessage)  //  //  Return value:  VOID  //  VOID CComAccess::ErrorToString(LPCSTR lpszMessage)  {      LPVOID lpMessageBuffer;      DWORD  error = GetLastError();      FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |                    FORMAT_MESSAGE_FROM_SYSTEM,      // source and processing options                    NULL,                            // pointer to message source                    error,                           // requested message identifie                    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // the user default language.                    (LPTSTR) &lpMessageBuffer,       // pointer to message buffer                    0,                               // maximum size of message buffer                    NULL);                           // address of array of message inserts       // and copy it in our error string      wsprintf(m_lpszErrorMessage,"%s: (%d) %s/n", lpszMessage, error, lpMessageBuffer);      LocalFree(lpMessageBuffer);  }  ////////////////////////////////////////////////////////////////////////////////////////  //   //  Function:     IsNT(VOID)  //  //  Return value: BOOL True or False  //  BOOL CComAccess::IsNT(VOID)  {      OSVERSIONINFO osvi;      osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);      GetVersionEx(&osvi);      if (osvi.dwPlatformId == VER_PLATFORM_WIN32_NT)       {          return TRUE;      }      else      {          return FALSE;      }  }