C# iText split PDF C# 拆分PDF

Nuget install iText7

using iText.Kernel.Pdf;

using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Configuration;
using iText.Kernel.Utils;
using iText.Kernel.Pdf;
using System.IO;
using System.Web.UI;
using System.Windows.Forms; 

class Program
    {
        static void Main(string[] args)
        {
            UltimateITextSplitPDF();
            Console.ReadLine();
        }

        static void UltimateITextSplitPDF()
        {
            string rawPdfFile = @"D:\C\C\ConsoleApp1\EJATT.pdf";
            Program objProvider = new Program();
            objProvider.PDFSplitExample(rawPdfFile);
        }      

        void PDFSplitExample(string rawPdfFile)
        {
            if(!File.Exists(rawPdfFile))
            {
                return;
            }
            MCSPdfSplitter mcsPdfSplitterProvider;
            //Generated physical split pdf files by GetNextPdfWriter of MCSPdfSplitter
            using (var pdfDoc = new PdfDocument(new PdfReader(rawPdfFile)))
            {
                mcsPdfSplitterProvider = new MCSPdfSplitter(pdfDoc, rawPdfFile);
                var splitPdfDocs = mcsPdfSplitterProvider.SplitByPageCount();
                foreach (var splitPDF in splitPdfDocs)
                {
                    splitPDF.Close();
                }
            }

            mcsPdfSplitterProvider.SplitPdfNamesList.ForEach(x =>
            {
                if (File.Exists(x))
                {
                    byte[] pdfByte = File.ReadAllBytes(x);
                    Console.WriteLine($"Before delete,Name {x},length {pdfByte.Length}");
                    File.Delete(x);
                }
            });
        }
}

using iText.Kernel.Utils;
using System;
using System.Collections.Generic;

namespace ConsoleApp1
{
public class MCSPdfSplitter : PdfSplitter
{
private int _pageNumber;
private string _rawPdfFile;
public List<string> SplitPdfNamesList = new List<string>();
public MCSPdfSplitter(PdfDocument pdfDocument, string rawPdfFile) : base(pdfDocument)
{
_rawPdfFile = rawPdfFile;
}

protected override PdfWriter GetNextPdfWriter(PageRange documentPageRange)
{
_pageNumber++;
string splitPDFFileName = _rawPdfFile.Substring(0,_rawPdfFile.LastIndexOf(".pdf"))+ _pageNumber+"split" + Guid.NewGuid().ToString().Replace("-", "") + ".pdf";
SplitPdfNamesList.Add(splitPDFFileName);
return new PdfWriter(splitPDFFileName);
}
}
}