How do I split and merge PDF?

Q: How do I split and merge PDF documents using PDFNet?

I followed instructions followed from :
but is there anything more simple. For example how do I split a PDF
file based on pages?

A: There are several APIs that can be used to split and merge pages
accross documents.

In the current version of PDFNet there are some utility functions
(pdfdoc.InsertPages() and pdfdoc.MovePages()) that can simplify page
splitting and merging operations. For example, the following snippet
can be used to split a PDF document into single page files:

using (PDFDoc doc = new PDFDoc(fileName)) {
  int num = doc.GetPageCount();
  for (int i=1; i<=num; ++i)
  using (PDFDoc new_doc = new PDFDoc()) {
    new_doc.InsertPages(0, doc, i, i, PDFDoc.InsertFlag.e_none);
    new_doc.Save(output_path, SDFDoc.SaveOptions.e_linearized);