win32API 读写ANSI\UNICODE\UNICODE BIG-ENDIAN\UTF-8格式文本

#include <windows.h>
#include <tchar.h>
#include <cassert>




//
//          读写文件的简单API函数封装
//                  CFileBaseHelper
//                           |
//                  -----------------
//                 |                 |
//          CFileReadHelper   CFileWriteHelper
//
/



//基类
enum FileTextType
{
  enANSI,       //
  enUTF8,       //EF BB BF
  enUnicode,      //FF FE
  enUnicodeBigEndian, //FE FF
  enUnknown
};

class CFileBaseHelper
{
public:
  CFileBaseHelper( LPCTSTR lpFileName);
  ~CFileBaseHelper();
  void CloseFile();

protected:
  FileTextType GetFileTextType(LPCTSTR lpFileName );

  FileTextType m_fttTextType;
  HANDLE m_hFile;
};

CFileBaseHelper::CFileBaseHelper( LPCTSTR lpFileName )
  :m_fttTextType( enUnknown ), m_hFile( INVALID_HANDLE_VALUE )
{
  assert( lpFileName != NULL );
  if( lpFileName == NULL )
  {
    return;
  }

  m_fttTextType = GetFileTextType(lpFileName);

  //打开文件
  m_hFile = CreateFile( lpFileName, 
    GENERIC_READ|GENERIC_WRITE, 
    FILE_SHARE_READ,
    NULL,
    OPEN_EXISTING, 
    0, 
    NULL );

}

CFileBaseHelper::~CFileBaseHelper()
{
  CloseFile();
}

void CFileBaseHelper::CloseFile()
{
  if( m_hFile != INVALID_HANDLE_VALUE )
  {
    CloseHandle( m_hFile );
    m_hFile = INVALID_HANDLE_VALUE;
  }
}



/*****************************************************************
* 时    间: [2015年11月1日]
* 作    者：shanql
* 函数描述：获取文本类型
* 函数参数：
* 函数返回：
*****************************************************************/
FileTextType CFileBaseHelper::GetFileTextType( LPCTSTR lpFileName )
{
  if( !lpFileName )
  {
    return enUnknown;
  }

  FileTextType fttTextType = enUnknown;

  //open file to read three byte 
  HANDLE hFile = CreateFile( lpFileName, 
    GENERIC_READ, 
    FILE_SHARE_READ | FILE_SHARE_WRITE,
    NULL, 
    OPEN_EXISTING, NULL, NULL );

  BYTE cbFlag[3] = { 0 };
  DWORD dwByteRead = 0;
  if( INVALID_HANDLE_VALUE != hFile &&
    ReadFile( hFile, cbFlag, 3, &dwByteRead, NULL ))
  {
    if( cbFlag[0] == 0xFF &&
      cbFlag[1] == 0xFE )
    {
      fttTextType = enUnicode;
    }
    else if ( cbFlag[0] == 0xFE &&
      cbFlag[1] == 0xFF )
    {
      fttTextType = enUnicodeBigEndian;
    }
    else if ( cbFlag[0] == 0xEF &&
      cbFlag[1] == 0xBB &&
      cbFlag[2] == 0xBF )
    {
      fttTextType = enUTF8;
    }
    else 
    {
      fttTextType = enANSI;
    }
  }

  CloseHandle( hFile );
  return fttTextType;
}



///
//读文件类
class CFileReadHelper:public CFileBaseHelper
{
public:
  CFileReadHelper( LPCTSTR lpFileName);
  BOOL ReadFile( LPVOID lpBuffer, DWORD dwByteToRead, LPDWORD lpByteRead ); 
};

CFileReadHelper::CFileReadHelper( LPCTSTR lpFileName )
  :CFileBaseHelper( lpFileName )
{

}

BOOL CFileReadHelper::ReadFile( LPVOID lpBuffer, DWORD dwByteToRead, LPDWORD lpByteRead )
{
  assert( m_hFile != INVALID_HANDLE_VALUE );
  if( m_hFile == INVALID_HANDLE_VALUE )
  {
    return FALSE;
  }

  assert( lpBuffer != NULL );
  if( lpBuffer == NULL )
  {
    return FALSE;
  }

  BOOL bReadResult = FALSE;
  switch( m_fttTextType )
  {
  case enANSI:
    {
      bReadResult = ::ReadFile( m_hFile, 
        lpBuffer, dwByteToRead, lpByteRead, NULL );
      break;
    }
  case enUnicode:
  case enUnicodeBigEndian:
    {
      //跳过前2个标记字节
      if( INVALID_SET_FILE_POINTER == SetFilePointer( m_hFile, 2, 0, FILE_BEGIN) )
      {
        if( GetLastError() != NOERROR )
        {
          return FALSE;
        }
      }

      bReadResult = ::ReadFile( m_hFile, 
        lpBuffer, dwByteToRead, lpByteRead, NULL );

      break;
    }
  case enUTF8:
    {
      //跳过前3个标记字节
      if( INVALID_SET_FILE_POINTER == SetFilePointer( m_hFile, 3, 0, FILE_BEGIN) )
      {
        if( GetLastError() != NOERROR )
        {
          return FALSE;
        }
      }

      bReadResult = ::ReadFile( m_hFile, 
        lpBuffer, dwByteToRead, lpByteRead, NULL );
      break;
    }
  default:
    {
      assert( false );
      return FALSE;
    }
  }

  return bReadResult;
}


//
//写文件类
class CFileWriteHelper : public CFileBaseHelper
{
public:
  CFileWriteHelper( LPCTSTR lpFileName);
  BOOL WriteFile( LPVOID lpBuffer, DWORD dwByteToWrite, LPDWORD lpByteWrite );
};

CFileWriteHelper::CFileWriteHelper( LPCTSTR lpFileName )
  :CFileBaseHelper( lpFileName )
{

}

BOOL CFileWriteHelper::WriteFile( LPVOID lpBuffer, DWORD dwByteToWrite, LPDWORD lpByteWrite )
{
  assert( m_hFile != INVALID_HANDLE_VALUE );
  if( m_hFile == INVALID_HANDLE_VALUE )
  {
    return FALSE;
  }

  assert( lpBuffer != NULL );
  if( lpBuffer == NULL )
  {
    return FALSE;
  }

  BOOL bWriteResult = FALSE;
  switch( m_fttTextType )
  {
  case enANSI:
    {
      bWriteResult = ::WriteFile( m_hFile, 
        lpBuffer, dwByteToWrite, lpByteWrite, NULL );
      break;
    }
  case enUnicode:
    { 
      if( INVALID_SET_FILE_POINTER == SetFilePointer( m_hFile, 0, 0, FILE_BEGIN) )
      {
        if( GetLastError() != NOERROR )
        {
          return FALSE;
        }
      }

      //在文件头先写入两个字节的标记 FF FE
      DWORD dwWriteHead = 0;
      BYTE cbHeadFlag[] = { 0xFF, 0xFE };
      if( !::WriteFile( m_hFile, cbHeadFlag, 2, &dwWriteHead, NULL ))
      {
        return FALSE;
      }

      bWriteResult = ::WriteFile( m_hFile, lpBuffer, dwByteToWrite, lpByteWrite, NULL );

      break;
    }
  case enUnicodeBigEndian:
    {
      if( INVALID_SET_FILE_POINTER == SetFilePointer( m_hFile, 0, 0, FILE_BEGIN) )
      {
        if( GetLastError() != NOERROR )
        {
          return FALSE;
        }
      }

      //在文件头先写入两个字节的标记 FE FF
      DWORD dwWriteHead = 0;
      BYTE cbHeadFlag[] = { 0xFE, 0xFF };
      if( !::WriteFile( m_hFile, cbHeadFlag, 2, &dwWriteHead, NULL ))
      {
        return FALSE;
      }

      bWriteResult = ::WriteFile( m_hFile, lpBuffer, dwByteToWrite, lpByteWrite, NULL );

      break;
    }
  case enUTF8:
    {
      if( INVALID_SET_FILE_POINTER == SetFilePointer( m_hFile, 0, 0, FILE_BEGIN) )
      {
        if( GetLastError() != NOERROR )
        {
          return FALSE;
        }
      }

      //在文件头先写入3个字节的标记 EF BB BF
      DWORD dwWriteHead = 0;
      BYTE cbHeadFlag[] = { 0xEF, 0xBB, 0xBF };
      if( !::WriteFile( m_hFile, cbHeadFlag, 3, &dwWriteHead, NULL ))
      {
        return FALSE;
      }

      bWriteResult = ::WriteFile( m_hFile, lpBuffer, dwByteToWrite, lpByteWrite, NULL );

      break;
    }
  default:
    {
      assert( false );
      return FALSE;
    }
  }

  return bWriteResult;
}


//测试函数 
void ReverseFileTest( LPCTSTR lpFileName )
{
  assert( lpFileName != NULL );
  if( lpFileName == NULL )
  {
    return;
  }

  CFileReadHelper tmpFileRead( lpFileName );
  BYTE szReadBuffer[1024] = { 0 };
  DWORD dwByteRead = 0;
  if( !tmpFileRead.ReadFile( szReadBuffer, sizeof(szReadBuffer), &dwByteRead ) )
  {
    _tprintf( TEXT("read file failed.\r\n"));
    return;
  }
  tmpFileRead.CloseFile();//可以不调用，析构时会自动调用


  //反转文件内容
  INT nStart = 0;
  INT nEnd = dwByteRead-1;
  BYTE cbTemp;
  while( nStart < nEnd )
  {
    cbTemp = szReadBuffer[nStart];
    szReadBuffer[nStart] = szReadBuffer[nEnd];
    szReadBuffer[nEnd] = cbTemp;

    ++nStart;
    --nEnd;
  }

  //写入文件
  CFileWriteHelper tmpFileWrite( lpFileName );
  DWORD dwByteWrite = 0;
  if( !tmpFileWrite.WriteFile( szReadBuffer, dwByteRead, &dwByteWrite ) )
  {
    _tprintf( TEXT("write file failed.\r\n") );
    return;
  }
  tmpFileWrite.CloseFile();//可以不调用，析构时会自动调用
}


int main()
{
  ReverseFileTest(TEXT("test_ansi.txt"));
  ReverseFileTest(TEXT("test_unicode.txt"));
  ReverseFileTest(TEXT("test_unicode_big_endian.txt"));
  ReverseFileTest(TEXT("test_utf8.txt"));
  return 0;
}

作者：山丘儿