C / C++ / MFC

while((uBytesRead = fileRead.Read(cBuf, sizeof(cBuf)-1)) != 0)

BOOL CMyTabCtrl::OnEraseBkgnd(CDC* pDC) 
{
	// TODO: Code für die Behandlungsroutine für Nachrichten hier einfügen und/oder Standard aufrufen

    // Set brush to desired background color
    CBrush backBrush(RGB(255, 0, 0));

    // Save old brush
    CBrush* pOldBrush = pDC->SelectObject(&backBrush);

    CRect rect;
    pDC->GetClipBox(&rect); // Erase the area needed

    pDC->PatBlt(rect.left, rect.top, rect.Width(), rect.Height(), PATCOPY);
    pDC->SelectObject(pOldBrush);
 
    return TRUE;
}

static _Convert ConvertLong (
    const char *pszValue, long *plValue) 
{

    //
    // Perform basic conversion
    //

    errno = 0;
    char *pszEnd = NULL;
    long lReturn = strtol (pszValue, &pszEnd, 10);

    //
    // Make sure that there isn't any trash at the end
    //

    if (pszEnd)
    {

        //
        // Skip whitespace
        //

        while (isspace (*pszEnd))
            pszEnd++;

        //
        // If the string is blank or there 
        // was trash, issue error
        //

        if (pszValue == pszEnd || *pszEnd != 0)
            return Convert_Invalid;
    }

    //
    // Check for overflow
    //

    if (errno == ERANGE)
    {
        if (lReturn < 0)
            return Convert_Underflow;
        else
            return Convert_Overflow;
    }
    *plValue = lReturn;
    return Convert_Ok;
}

enum NumericFlag
{
	Unsigned,		// can only be positive and non-decimal
	Signed,		// can be positive or negative
	Decimal,		// can be positive and have a decimal point
	SignedDecimal	// can be positive or negative and have a decimal point
};
 
// Returns true if self is a valid number based on the given flag.
bool IsNumeric(const char* szValue, NumericFlag flag /*= Unsigned*/) const
{
	assert(szValue);
	int nLen = strlen(szValue);
 
	// Check every character individually
	for (int iPos = 0, nDecimalPos = -1; iPos < nLen; iPos++)
	{
		char c = szValue[iPos];
 
		// Check for a digit
		if (isdigit(c))
			continue;
 
		// Check for a negative sign
		if (c == '-' && iPos == 0 && (flag & Signed))
			continue;
 
		// Check for a decimal point
		if (c == '.' && nDecimalPos < 0 && (flag & Decimal))
		{
			nDecimalPos = iPos;
			continue;
		}
 
		return false;
	}
 
	return !!nLen;  // if it's empty, it's not a valid number
}