iTextSharp.text.pdf.PdfWriter.RegisterLayer C# (CSharp) Méthode

        internal void RegisterLayer(IPdfOCG layer)
        {
            PdfWriter.CheckPdfIsoConformance(this, PdfIsoKeys.PDFISOKEY_LAYER, null);
            if (layer is PdfLayer) {
                PdfLayer la = (PdfLayer)layer;
                if (la.Title == null) {
                    if (!documentOCG.ContainsKey(layer)) {
                        documentOCG[layer] = null;
                        documentOCGorder.Add(layer);
                    }
                }
                else {
                    documentOCGorder.Add(layer);
                }
            }
            else
                throw new ArgumentException(MessageLocalization.GetComposedMessage("only.pdflayer.is.accepted"));
        }

 /**
 * Creates a title layer. A title layer is not really a layer but a collection of layers
 * under the same title heading.
 * @param title the title text
 * @param writer the <CODE>PdfWriter</CODE>
 * @return the title layer
 */    
 public static PdfLayer CreateTitle(String title, PdfWriter writer) {
     if (title == null)
         throw new ArgumentNullException(MessageLocalization.GetComposedMessage("title.cannot.be.null"));
     PdfLayer layer = new PdfLayer(title);
     writer.RegisterLayer(layer);
     return layer;
 }