Page rating	64% for 9 votes	Useless Brilliant

Description.

Accessing data in files is a key part of software development. Here are some simple samples of file I/O that include error trapping. 

Read a file into a CString.

bool LoadFile( CString sFileName, CString *psLoad )
{
    TRACE( _T("LoadFile(%s,0x%p)\n"), sFileName, psLoad );
    ASSERT( psLoad );
    TRY
    {
        CFile fileIn( sFileName, CFile::modeRead );
        int nLen = fileIn.GetLength();
        if( nLen > 0 )
        {
            fileIn.Read( psLoad->GetBuffer( nLen ), nLen );
            psLoad->ReleaseBuffer();
        }
        fileIn.Close();
    }
    CATCH(CFileException, pEx)
    {
        //Show error message
        CString sErrorMess;
        TCHAR   szCause[255];
        pEx->GetErrorMessage(szCause, 255);
        sErrorMess.Format( _T("Error %s\n Reading %s"), 
            szCause, 
            pEx->m_strFileName );
        AfxMessageBox( sErrorMess );
        return false;
    }
    AND_CATCH(CMemoryException, pEx)
    {
        //Memory execption are often associated with 
        //CString objects. Normally, an application should 
        // do everything it possibly can to
        // clean up properly and _not_ call AfxAbort().
        AfxAbort();
        return false;
    }
    END_CATCH;
    return true;
}

Save a CString to a file.

bool SaveFile( CString sFileName, CString sSave )
{
    TRACE( _T("SaveFile(%s,sSave)\n"), sFileName );
    TRY
    {
        CFile fileOut( sFileName, 
            CFile::modeCreate | CFile::modeWrite );
        int nLen = sSave.GetLength();
        if( nLen > 0 )
        {
            fileOut.Write( sSave.GetBuffer( nLen ), nLen );
            sSave.ReleaseBuffer();
        }
        fileOut.Close();
    }
    CATCH(CFileException, pEx)
    {
        //Show error message
        CString sErrorMess;
        TCHAR   szCause[255];
        pEx->GetErrorMessage(szCause, 255);
        sErrorMess.Format( _T("Error %s\n Writing %s"), 
            szCause, 
            pEx->m_strFileName );
        AfxMessageBox( sErrorMess );
        return false;
    }
    AND_CATCH(CMemoryException, pEx)
    {
        //Memory execption are often associated with 
        //CString objects. Normally, an application should 
        // do everything it possibly can to
        // clean up properly and _not_ call AfxAbort().
        AfxAbort();
        return false;
    }
    END_CATCH;
    return true;
}