Why does FileStream feed FtpWebRequest but not MemoryStream?

Question

I'm using the msdn example here: http://msdn.microsoft.com/en-us/library/system.net.ftpwebrequest.aspx

I changed the FileStream to a MemoryStream and it doesn't read the bytes

when I change it back to FileStream it works fine.

Any clue?

Thanks

        CompressMemoryStream();
        Stream requestStream = _request.EndGetRequestStream(ar);
        const int bufferLength = 2048;
        byte[] buffer = new byte[bufferLength];
        int count = 0;
        int readBytes = 0;

        do
        {
            //MemoryStream _compressedOutStream 
            //is created/filled by 'CompressMemoryStream()'
            readBytes = _compressedOutStream.Read(buffer, 0, bufferLength);
            requestStream.Write(buffer, 0, readBytes);
            count += readBytes;
        }
        while (readBytes != 0);
        requestStream.Close();
        state.Request.BeginGetResponse(
            new AsyncCallback(EndGetResponseCallback),
            state
        );

Answer 1

What's the value of readBytes on the first iteration through the loop?

My first guess would be that you made the same mistake that I often make: writing to a stream, then forgetting to rewind it to the beginning before starting to read back from it. If that's the case, then readBytes will be zero on the first (and only) loop iteration, because you're at the end of the stream -- there's nothing to read.

Try setting stream.Position = 0 before you start reading.