C# Code to Split , Merge PDF files

Split the PDF File
---------------------
filepath--- The Path of the Source PDF File need to Split.

dirPath---The Path of the Destination Folder, the splited files need to be saved.

private void SplitPDF(string filepath)

        {

           

            PdfReader reader = null;

            int currentPage = 1;

            int pageCount = 0;

          

            System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();

            reader = new iTextSharp.text.pdf.PdfReader(filepath);

            reader.RemoveUnusedObjects();

            pageCount = reader.NumberOfPages;

            string ext = System.IO.Path.GetExtension(filepath);

            for (int i = 1; i <= pageCount; i++)

            {

                iTextSharp.text.pdf.PdfReader reader1 = new iTextSharp.text.pdf.PdfReader(filepath);

                string outfile = filepath.Replace((System.IO.Path.GetFileName(filepath)), (System.IO.Path.GetFileName(filepath).Replace(".pdf", "") + "_" + i.ToString()) + ext);

                outfile = outfile.Substring(0, dirPath.Length).Insert(dirPath.Length, "\\Images\\PDFSplit") + "\\" + Path.GetFileName(filepath).Replace(".pdf", "") + "_" + i.ToString() + ext;

                reader1.RemoveUnusedObjects();

                iTextSharp.text.Document doc = new iTextSharp.text.Document(reader.GetPageSizeWithRotation(currentPage));

                iTextSharp.text.pdf.PdfCopy pdfCpy = new iTextSharp.text.pdf.PdfCopy(doc, new System.IO.FileStream(outfile, System.IO.FileMode.Create));

                doc.Open();

                for (int j = 1; j <= 1; j++)

                {

                    iTextSharp.text.pdf.PdfImportedPage page = pdfCpy.GetImportedPage(reader1, currentPage);

                    pdfCpy.SetFullCompression();

                    pdfCpy.AddPage(page);

                    currentPage += 1;

                }

                doc.Close();

                pdfCpy.Close();

                reader1.Close();

                reader.Close();

            }

        }

Merge the Multiple PDF Files into one File
--------------------------------------------------
SourceFiles--- The Path of the Source PDF Files need to Merge.

DestinationFile---The Path of the Destination Folder, the Merged file need to be saved.

        public void MergePdf(string destinationFile, string[] sourceFiles)

        {

            try

            {

                int f = 0;

                

                PdfReader reader = new PdfReader(sourceFiles[f]);

                int n = reader.NumberOfPages;

                

                Document document = new Document(reader.GetPageSizeWithRotation(1));

               

                PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(destinationFile, FileMode.Create));

              

                document.Open();

                PdfContentByte cb = writer.DirectContent;

                PdfImportedPage page;

                int rotation;

               

                while (f < sourceFiles.Length)

                {

                    int i = 0;

                    while (i < n)

                    {

                        i++;

                        document.SetPageSize(reader.GetPageSizeWithRotation(i));

                        document.NewPage();

                        page = writer.GetImportedPage(reader, i);

                        rotation = reader.GetPageRotation(i);

                        if (rotation == 90 || rotation == 270)

                        {

                            cb.AddTemplate(page, 0, -1f, 1f, 0, 0, reader.GetPageSizeWithRotation(i).Height);

                        }

                        else

                        {

                            cb.AddTemplate(page, 1f, 0, 0, 1f, 0, 0);

                        }

                

                    }

                    f++;

                    if (f < sourceFiles.Length)

                    {

                        reader = new PdfReader(sourceFiles[f]);

                       

                        n = reader.NumberOfPages;

                    }

                }

               

                document.Close();

            }

            catch (Exception e)

            {

                string strOb = e.Message;

            }

        }