static void AddPackage(PDFDoc doc, string file, string desc)
{
NameTree files = NameTree.Create(doc, "EmbeddedFiles");
FileSpec fs = FileSpec.Create(doc, file, true);
byte[] file1_name = System.Text.Encoding.UTF8.GetBytes(file);
files.Put(file1_name, fs.GetSDFObj());
fs.GetSDFObj().PutText("Desc", desc);
Obj collection = doc.GetRoot().FindObj("Collection");
if (collection == null)
{
collection = doc.GetRoot().PutDict("Collection");
}
// You could here manipulate any entry in the Collection dictionary.
// For example, the following line sets the tile mode for initial view mode
// Please refer to section '2.3.5 Collections' in PDF Reference for details.
collection.PutName("View", "T");
}