自学教程：C++ AfxThrowFileException函数代码示例

UINT CStdioFile::Read(void* lpBuf, UINT nCount){	ASSERT_VALID(this);	ASSERT(m_pStream != NULL);	if (nCount == 0)		return 0;   // avoid Win32 "null-read"	ASSERT(AfxIsValidAddress(lpBuf, nCount));	if (lpBuf == NULL)	{		AfxThrowInvalidArgException();	}	UINT nRead = 0;	if ((nRead = (UINT)fread(lpBuf, sizeof(BYTE), nCount, m_pStream)) == 0 && !feof(m_pStream))		AfxThrowFileException(CFileException::genericException, _doserrno, m_strFileName);	if (ferror(m_pStream))	{		Afx_clearerr_s(m_pStream);		AfxThrowFileException(CFileException::genericException, _doserrno, m_strFileName);	}	return nRead;}

UINT CBuffFile::Read(void* lpBuf, UINT nCount){	UINT nRead = 0;	if ((nRead = fread(lpBuf, sizeof(BYTE), nCount, m_pStream)) == 0 && !feof(m_pStream))		AfxThrowFileException(CFileException::generic, _doserrno);	if (ferror(m_pStream))	{		clearerr(m_pStream);		AfxThrowFileException(CFileException::generic, _doserrno);	}	return nRead;}

LONG CMyMemFile::Seek(LONG lOff, UINT nFrom){    switch(nFrom)    {    case CFile::begin:        if(NULL != m_pData)        {            m_pData -= m_dwLength;            m_pData += lOff;        }        m_dwLength = lOff;        break;    case CFile::current:        if(NULL != m_pData)        {            m_pData += lOff;        }        m_dwLength += lOff;        break;    case CFile::end:    default:        AfxThrowFileException(CFileException::badSeek);    }    return m_dwLength;}

void PASCAL CFileException::ThrowErrno(int nErrno,	LPCTSTR lpszFileName /* = NULL */){	if (nErrno != 0)		AfxThrowFileException(CFileException::ErrnoToException(nErrno),			_doserrno, lpszFileName);}

void CStdioFileEx::WriteWideString(LPCWSTR lpsz){   ASSERT(lpsz != NULL);      if (lpsz == NULL)   {      AfxThrowInvalidArgException();   }   if(m_bIsUnicodeText)   {      ASSERT(m_pStream != NULL);      // If writing Unicode and at the start of the file, need to write byte mark      if(GetPosition() == 0)      {         wchar_t cBOM = (wchar_t)UNICODE_BOM;         CFile::Write(&cBOM, sizeof(wchar_t));      }      if (fputws(lpsz, m_pStream) == _TEOF)         AfxThrowFileException(CFileException::diskFull, _doserrno, m_strFileName);   }   else   {      USES_CONVERSION;      WriteAnsiString(CW2A(lpsz));   }}

UINT CConverter::Read(void FAR* lpBuf, UINT nCount){	ASSERT(m_bForeignToRtf);	if (m_bDone)		return 0;	// if converter is done	int cch = nCount;	BYTE* pBuf = (BYTE*)lpBuf;	while (cch != 0)	{		if (m_nBytesAvail == 0)		{			if (m_pBuf != NULL)				GlobalUnlock(m_hBuff);			m_pBuf = NULL;			SetEvent(m_hEventConv);			WaitForConverter();			VERIFY(ResetEvent(m_hEventFile));			if (m_bConvErr)				AfxThrowFileException(CFileException::generic);			if (m_bDone)				return nCount - cch;			m_pBuf = (BYTE*)GlobalLock(m_hBuff);			ASSERT(m_pBuf != NULL);		}		int nBytes = min(cch, m_nBytesAvail);		memcpy(pBuf, m_pBuf, nBytes);		pBuf += nBytes;		m_pBuf += nBytes;		m_nBytesAvail -= nBytes;		cch -= nBytes;		OutputPercent(m_nPercent);	}	return nCount - cch;}

COXRegistryValFile::COXRegistryValFile(HKEY hkey, LPCTSTR lpszKey, LPCTSTR lpszValue)	: CMemFile(1024), m_key(0)	{	LONG error;	if (!Open(hkey, lpszKey, lpszValue, error))		AfxThrowFileException(CFileException::accessDenied, error, lpszKey);	}

uint64 CSafeMemFile::ReadUInt64(){	if (m_nPosition + sizeof(uint64) > m_nFileSize)		AfxThrowFileException(CFileException::endOfFile, 0, GetFileName());	uint64 nResult = *((uint64*)(m_lpBuffer + m_nPosition));	m_nPosition += sizeof(uint64);	return nResult;}

void CStdioFile::WriteString(LPCTSTR lpsz){	ASSERT(lpsz != NULL);	ASSERT(m_pStream != NULL);	if (_fputts(lpsz, m_pStream) == _TEOF)		AfxThrowFileException(CFileException::diskFull, _doserrno, m_strFileName);}

void CStdioFile::Flush(){	ASSERT_VALID(this);	if (m_pStream != NULL && fflush(m_pStream) != 0)		AfxThrowFileException(CFileException::diskFull, _doserrno,			m_strFileName);}

int CSafeBufferedFile::printf(LPCTSTR pszFmt, ...){	va_list args;	va_start(args, pszFmt);	int iResult = _vftprintf(m_pStream, pszFmt, args);	va_end(args);	if (iResult < 0)		AfxThrowFileException(CFileException::generic, _doserrno, m_strFileName);	return iResult;}

void PASCAL CFileException::ThrowErrno(int nErrno){	if (nErrno != 0)		AfxThrowFileException(CFileException::ErrnoToException(nErrno),#ifndef _MAC			_doserrno);#else			GetLastError());#endif}

void CSocketFile::Write(const void* lpBuf, UINT nCount){	ASSERT (m_pSocket!=NULL);	int nWritten = m_pSocket->Send(lpBuf, nCount);	if (nWritten == SOCKET_ERROR)	{		int nError = m_pSocket->GetLastError();		AfxThrowFileException(CFileException::generic, nError);	}}

BOOL CStdioFileEx::ReadWideString(CStringW& rString){   _ASSERTE(m_pStream);   rString = L"";// empty string without deallocating      if(m_bIsUnicodeText)   {      // If at position 0, discard byte-order mark before reading      if(GetPosition() == 0)      {         wchar_t bom;         Read(&bom, sizeof(wchar_t));      }      const int nMaxSize = 128;      LPWSTR lpsz = rString.GetBuffer(nMaxSize);      LPWSTR lpszResult;      int nLen = 0;      for (;;)      {         lpszResult = fgetws(lpsz, nMaxSize+1, m_pStream);         rString.ReleaseBuffer();                  // handle error/eof case         if (lpszResult == NULL && !feof(m_pStream))         {            Afx_clearerr_s(m_pStream);            AfxThrowFileException(CFileException::genericException, _doserrno,               m_strFileName);         }                  // if string is read completely or EOF         if (lpszResult == NULL || (nLen = (int)lstrlenW(lpsz)) < nMaxSize || lpsz[nLen-1] == '/n')            break;                  nLen = rString.GetLength();         lpsz = rString.GetBuffer(nMaxSize + nLen) + nLen;      }      //remove crlf if exist.      nLen = rString.GetLength();      if (nLen > 1 && rString.Mid(nLen-2) == L"/r/n")      {         rString.GetBufferSetLength(nLen-2);      }      return rString.GetLength() > 0;   }   else   {      CStringA ansiString;      BOOL bRetval = ReadAnsiString(ansiString);      //setlocale(LC_ALL, "chs_chn.936");//no need      rString = ansiString;      return bRetval;   }}

void CBuffFile::Close(){	int nErr= 0;	if (m_pStream != NULL)		nErr = fclose(m_pStream);	m_hFile = hFileNull;	m_bCloseOnDelete = FALSE;	m_pStream = NULL;	if (nErr != 0)		AfxThrowFileException(CFileException::diskFull, _doserrno);}

void CStdioFileT::WriteString(LPCWSTR lpsz){	ASSERT(lpsz != NULL);	ASSERT(m_pStream != NULL);	if (lpsz == NULL)	{		AfxThrowInvalidArgException();	}	if (fputws(lpsz, m_pStream) == EOF)		AfxThrowFileException(CFileException::diskFull, _doserrno, m_strFileName);}

void CDocument::SetPathName(LPCTSTR lpszPathName, BOOL bAddToMRU){	// store the path fully qualified	TCHAR szFullPath[_MAX_PATH];	if ( lstrlen(lpszPathName) >= _MAX_PATH )	{		ASSERT(FALSE);		// MFC requires paths with length < _MAX_PATH		// No other way to handle the error from a void function		AfxThrowFileException(CFileException::badPath);	}	if( AfxFullPath(szFullPath, lpszPathName) == FALSE )	{		ASSERT(FALSE);		// MFC requires paths with length < _MAX_PATH		// No other way to handle the error from a void function		AfxThrowFileException(CFileException::badPath);	}	m_strPathName = szFullPath;	ASSERT(!m_strPathName.IsEmpty());       // must be set to something	m_bEmbedded = FALSE;	ASSERT_VALID(this);	// set the document title based on path name	TCHAR szTitle[_MAX_FNAME];	if (AfxGetFileTitle(szFullPath, szTitle, _MAX_FNAME) == 0)		SetTitle(szTitle);	// add it to the file MRU list	if (bAddToMRU)		AfxGetApp()->AddToRecentFileList(m_strPathName);	ASSERT_VALID(this);}