CFile vs. CStdioFile parsing CSV files

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C++

MFC

How do I use CStdioFile?

I read MSDN and it is kindof vague, I would like to convert from CFile to CStdioFile so I can use the CStdioFile::ReadString member. Do I read the file line by line into a buffer until the buffer holds the whole file or do I read one line into the buffer then parse? Below is working with about 85% efficiently along with the rest of the app.(unacceptable!) I believe the ReadString method will get me to 100%(when I learn the logic of CStdioFile)

/************************************************************************/
/*  Create handle to my file and open it                                */
/************************************************************************/
    CFile myFile;
    CFileException e;       
    BYTE buffer[0x1000];    //4kb(4,096Bytes) buffer to hold csv file

    if(myFile.Open(_T("c:\\myDir\\subDir\\accounts.csv"), CFile::modeRead, &e) == 0)
    {
        e.ReportError();
        e.Delete();
    }

    DWORD dwBytesRemaining = myFile.GetLength();
/************************************************************************/
/*  Read file into buffer, while created a new buffer and adding to it  */
/*      4KB at a time.                                                  */
/************************************************************************/
    while(dwBytesRemaining)
    {
        UINT nBytesRead = myFile.Read(buffer, sizeof(buffer));
        for(int i = 0; i <= sizeof(buffer); i++)
        {
            myBuffer += buffer[i];
        }
        dwBytesRemaining -= nBytesRead;
    }

When I change CFile to CStdioFile and set it up the way I think it will work, it parses the first line at 100% and then I get an assertion error. I'm a little lost using CStdioFile.
_______________________________________________________________________

OK!

Here is the version with CStdioFile, it parses the last line in the file perfectly. How can I start at the beginning of the file? I have "logic brain block syndrome", I can not think of a way to process the whole file. I really need some pointers with this.

/************************************************************************/
/*  Create handle to file and open it   "CStdioFile Section             */
/************************************************************************/
    CFileException cStderr;
    CStdioFile cStdFile;

    if(!cStdFile.Open(_T("c:\\myDir\\subDir\\accountscsv.csv"), CFile::modeRead, &cStderr))
    {
        cStderr.ReportError();
        cStderr.Delete();
    }
/************************************************************************/
/*  Read file 1 line at a time and parse by CSV         "CStdioFile"    */
/************************************************************************/
    CString cStdstr(_T(""));

    while(cStdFile.ReadString(cStdstr))
    {
        int nValues = 0;
        LPCTSTR q = cStdstr;

        while (*q != '\0')  //Keep reading until end of line is reached
        {
            // String to hold parsed value
            CString t;
            if(*q == '"')
                q++;
            //Add characters to t until a comma or EOL
            while (*q != '\0' && *q != ',')
            {
                if(*q == '"')
                    q++;
                if(*q == ',')
                    break;
                t.AppendChar(*q++);
            }
            // Advance to next character (if not already end of string)
            if (*q != '\0')
                q++;
            // Add this string to value array
            if (nValues < cStdioArr.GetCount())
            {
                t.Trim(' ');
                cStdioArr[nValues] = t;
            }
            else
            {
                t.Trim(' ');
                cStdioArr.Add(t);
            }
            nValues++;
        }
    // Trim off any unused array values
    if (cStdioArr.GetCount() > nValues)
        cStdioArr.RemoveAt(nValues, cStdioArr.GetCount() - nValues);
    }