> I'm creating a class to read some text datafiles.
>
> These files start with a header with variable length, followed by a section
> with data values (numbers in separate lines) also with variable length. The
> data section must be read sequentialy, so my approch to this is:
>
> -Read the header (line by line) until find the header's end.
> -Store the Position of the BaseStream property of the StreamReader
> -Read the data section (also line by line)
>
> I need to store the stream position before start reading the data section,
> to be able to re-read the data without having to parse the header again.
>
> The problem is that the StreamReader buffers data, so the value returned in
> BaseStream.Position property is always ahead of the actual processed line.
>
> I understand that we need to call DiscardBufferedData after seeking in the
> base stream, so we start to read in the right position.
>
> But how can I know the exact position, discarding the buffered data that was
> not returned in the ReadLine method?

"Jon Skeet [C# MVP]" wrote:

> ferreira <ferre***@discussions.microsoft.com> wrote:
> > I'm creating a class to read some text datafiles.
> >
> > These files start with a header with variable length, followed by a section
> > with data values (numbers in separate lines) also with variable length. The
> > data section must be read sequentialy, so my approch to this is:
> >
> > -Read the header (line by line) until find the header's end.
> > -Store the Position of the BaseStream property of the StreamReader
> > -Read the data section (also line by line)
> >
> > I need to store the stream position before start reading the data section,
> > to be able to re-read the data without having to parse the header again.
> >
> > The problem is that the StreamReader buffers data, so the value returned in
> > BaseStream.Position property is always ahead of the actual processed line.
> >
> > I understand that we need to call DiscardBufferedData after seeking in the
> > base stream, so we start to read in the right position.
> >
> > But how can I know the exact position, discarding the buffered data that was
> > not returned in the ReadLine method?
>
> I'm afraid you can't, as far as I know. If the file is encoded in a
> text encoding which is fixed-width, you could keep track of how much
> text has been read and multiply that by the width, but that's the only
> solution I know of :(
>
> --
> Jon Skeet - <sk***@pobox.com>
> http://www.pobox.com/~skeet   Blog: http://www.msmvps.com/jon.skeet
> If replying to the group, please do not mail me too
>