C#代码实现获取PDF文件的页数

PM> Install-Package Spire.PDF

using Spire.Pdf;

namespace GetNumberOfPages
{
    class Program
    {
        static void Main(string[] args)
        {
            // 创建 PdfDocument 对象
            PdfDocument pdf = new PdfDocument();

            // 加载示例 PDF 文件
            pdf.LoadFromFile("Contract.pdf");

            // 获取 PDF 文件的页数
            int PageNumber = pdf.Pages.Count;
            Console.WriteLine("该 PDF 文件共有 {0} 页", PageNumber);

            // 关闭 PDF 文档
            pdf.Close();
        }
    }
}

        /// <summary>
        /// 获取pdf文档的页数
        /// </summary>
        /// <param name="filePath"></param>
        /// <returns>-1表示文件不存在</returns>
        public static int GetPDFofPageCount(string filePath)
        {
            int count = -1;//-1表示文件不存在
            if (File.Exists(filePath))
            {
                using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read))
                {
                    StreamReader reader = new StreamReader(fs);
                    //从流的当前位置到末尾读取流
                    string pdfText = reader.ReadToEnd();
                    Regex rgx = new Regex(@"/Type\s*/Page[^s]");
                    MatchCollection matches = rgx.Matches(pdfText);
                    count = matches.Count;
                }
            }
            return count;
        }

  /// <summary>
        /// 获取pdf文档的页数
        /// </summary>
        /// <param name="filePath"></param>
        /// <returns>-1表示文件不存在</returns>
        public static int GetPDFofPageCount(string filePath)
        {
            int count = -1;//-1表示文件不存在
            if (File.Exists(filePath))
            {
                using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read))
                {
                    StreamReader reader = new StreamReader(fs);
                    //从流的当前位置到末尾读取流
                    string pdfText = reader.ReadToEnd();
                    Regex rgx = new Regex(@"/Type\s*/Page[^s]");
                    MatchCollection matches = rgx.Matches(pdfText);
                    count = matches.Count;
                }
            }
            return count;
        }

public class pdfPage : PdfPageEventHelper
{              
    public override void OnEndPage(PdfWriter writer, Document doc)
    {
        iTextSharp.text.Rectangle page = doc.PageSize;
        //PdfPTable EndTable = new PdfPTable(2);
        PdfPTable EndTable = new PdfPTable(2);
        EndTable.DefaultCell.Padding = 2f;
        EndTable.HorizontalAlignment = Element.ALIGN_JUSTIFIED;
        iTextSharp.text.Font smallfont2 = FontFactory.GetFont(FontFactory.HELVETICA, "CP1250", 10);
        PdfPCell stopka1 = new PdfPCell(new Phrase("Left column - not important", smallfont2));
        stopka1.BorderWidthLeft = 0;
        stopka1.BorderWidthBottom = 0;
        stopka1.BorderWidthRight = 0;
        stopka1.HorizontalAlignment = Element.ALIGN_LEFT;
        stopka1.VerticalAlignment = Element.ALIGN_MIDDLE;
        PdfPCell stopka2 = new PdfPCell(new Phrase("Page " + doc.PageNumber + "/", smallfont2));
        stopka2.BorderWidthLeft = 0;
        stopka2.BorderWidthBottom = 0;
        stopka2.BorderWidthRight = 0;
        stopka2.HorizontalAlignment = Element.ALIGN_RIGHT;
        stopka2.VerticalAlignment = Element.ALIGN_MIDDLE;
        EndTable.AddCell(stopka1);
        EndTable.AddCell(stopka2);
        EndTable.TotalWidth = page.Width - doc.LeftMargin - doc.RightMargin;
        EndTable.WriteSelectedRows(0, -1, doc.LeftMargin, EndTable.TotalHeight + doc.BottomMargin - 45, writer.DirectContent);
    }
   }