private int EvalLength(ElementInstance parent, Stream stream, long stopAt)
{
int len = 0;
if (Length == null)
{
Debug.Assert(stopAt >= stream.Position);
len = (int)((stopAt - stream.Position) / DataElement.Size);
}
else
{
try
{
len = Convert.ToInt32(Length);
}
catch (FormatException)
{
IConvertible evalLen = parent.Eval(Length) as IConvertible;
if (evalLen != null)
{
len = evalLen.ToInt32(null);
}
}
}
return len;
}
