iTextSharp.text.pdf.PdfStream.WriteLength C# (CSharp) Метод

        public void WriteLength()
        {
            if (inputStream == null)
                throw new PdfException(MessageLocalization.GetComposedMessage("writelength.can.only.be.called.in.a.contructed.pdfstream.inputstream.pdfwriter"));
            if (inputStreamLength == -1)
                throw new PdfException(MessageLocalization.GetComposedMessage("writelength.can.only.be.called.after.output.of.the.stream.body"));
            writer.AddToBody(new PdfNumber(inputStreamLength), iref, false);
        }

        // ---------------------------------------------------------------------------
        public void Write(Stream stream)
        {
            // step 1
              using (Document document = new Document()) {
            // step 2
            PdfWriter writer = PdfWriter.GetInstance(document, stream);
            // step 3
            document.Open();
            // step 4
            Rectangle rect = new Rectangle(100, 400, 500, 800);
            rect.Border = Rectangle.BOX;
            rect.BorderWidth = 0.5f;
            rect.BorderColor = new BaseColor(0xFF, 0x00, 0x00);
            document.Add(rect);

            PdfIndirectObject streamObject = null;
            using (FileStream fs =
              new FileStream(RESOURCE, FileMode.Open, FileAccess.Read))
            {
              PdfStream stream3D = new PdfStream(fs, writer);

              stream3D.Put(PdfName.TYPE, new PdfName("3D"));
              stream3D.Put(PdfName.SUBTYPE, new PdfName("U3D"));
              stream3D.FlateCompress();
              streamObject = writer.AddToBody(stream3D);
              stream3D.WriteLength();
            }

            PdfDictionary dict3D = new PdfDictionary();
            dict3D.Put(PdfName.TYPE, new PdfName("3DView"));
            dict3D.Put(new PdfName("XN"), new PdfString("Default"));
            dict3D.Put(new PdfName("IN"), new PdfString("Unnamed"));
            dict3D.Put(new PdfName("MS"), PdfName.M);
            dict3D.Put(
              new PdfName("C2W"),
              new PdfArray(
            new float[] { 1, 0, 0, 0, 0, -1, 0, 1, 0, 3, -235, 28 }
              )
            );
            dict3D.Put(PdfName.CO, new PdfNumber(235));

            PdfIndirectObject dictObject = writer.AddToBody(dict3D);

            PdfAnnotation annot = new PdfAnnotation(writer, rect);
            annot.Put(PdfName.CONTENTS, new PdfString("3D Model"));
            annot.Put(PdfName.SUBTYPE, new PdfName("3D"));
            annot.Put(PdfName.TYPE, PdfName.ANNOT);
            annot.Put(new PdfName("3DD"), streamObject.IndirectReference);
            annot.Put(new PdfName("3DV"), dictObject.IndirectReference);
            PdfAppearance ap = writer.DirectContent.CreateAppearance(
              rect.Width, rect.Height
            );
            annot.SetAppearance(PdfAnnotation.APPEARANCE_NORMAL, ap);
            annot.SetPage();

            writer.AddAnnotation(annot);
              }
        }