// Standard ctor - as for BlobReadStream but also specify the offset and number of bytes for the partial read.
public PartialBlobReadStream(Stream s, FPTag t, long offset, long numBytes)
{
// We cannot call the base constructor because we need use the additional offset and numBytes parameters
// Even if we split out some of the functionality using a virtual init method with no
// parameters, these paraameters will not be initialized when the virtual function was called
// by the base constructor. So we just have to duplicate the (small)initialization code.
holdingArea = s;
theTag = t;
myCallbacks = new Callbacks(holdingArea, 16 * 1024);
fpStream = new FPGenericStream(holdingArea, FPStream.StreamDirection.OutputFromCentera, myCallbacks, IntPtr.Zero);
fpStream.StreamLen = numBytes;
blobThread = new Thread(delegate() { theTag.BlobReadPartial(fpStream, offset, numBytes); });
blobThread.Name = "PartialBlobReadThread";
blobThread.Start();
}
