PM> Install-Package Spire.PDF

using Spire.Pdf;
using Spire.Pdf.Actions;
using Spire.Pdf.Annotations;
using Spire.Pdf.General;
using Spire.Pdf.Graphics;
using System;
using System.Drawing;

namespace TableOfContents
{
    internal class Program
    {
        static void Main(string[] args)
        {
            //初始化 PdfDocument 類的實例
            PdfDocument doc = new PdfDocument();
            //加載 PDF 文檔
            doc.LoadFromFile("Sample.PDF");

            //獲取文檔的頁數(shù)
            int pageCount = doc.Pages.Count;

            //在文檔開頭插入一個新頁面作為目錄頁
            PdfPageBase tocPage = doc.Pages.Insert(0);

            //在新頁面上繪制目錄標題
            string title = "Table of Contents";
            PdfTrueTypeFont titleFont = new PdfTrueTypeFont(new Font("Arial", 20, FontStyle.Bold));
            PdfStringFormat centerAlignment = new PdfStringFormat(PdfTextAlignment.Center, PdfVerticalAlignment.Middle);
            PointF location = new PointF(tocPage.Canvas.ClientSize.Width / 2, titleFont.MeasureString(title).Height + 10);
            tocPage.Canvas.DrawString(title, titleFont, PdfBrushes.CornflowerBlue, location, centerAlignment);

            //在新頁面上繪制目錄內(nèi)容
            PdfTrueTypeFont titlesFont = new PdfTrueTypeFont(new Font("Arial", 14));
            String[] titles = new String[pageCount];
            for (int i = 0; i < titles.Length; i++)
            {
                titles[i] = string.Format("This is page {0}", i + 1);
            }
            float y = titleFont.MeasureString(title).Height + 10;
            float x = 0;

            //在新頁面上繪制目標頁的頁碼
            for (int i = 1; i <= pageCount; i++)
            {
                string text = titles[i - 1];
                SizeF titleSize = titlesFont.MeasureString(text);

                PdfPageBase navigatedPage = doc.Pages[i];

                string pageNumText = (i + 1).ToString();
                SizeF pageNumTextSize = titlesFont.MeasureString(pageNumText);
                tocPage.Canvas.DrawString(text, titlesFont, PdfBrushes.CadetBlue, 0, y);
                float dotLocation = titleSize.Width + 2 + x;
                float pageNumlocation = tocPage.Canvas.ClientSize.Width - pageNumTextSize.Width;
                for (float j = dotLocation; j < pageNumlocation; j++)
                {
                    if (dotLocation >= pageNumlocation)
                    {
                        break;
                    }
                    tocPage.Canvas.DrawString(".", titlesFont, PdfBrushes.Gray, dotLocation, y);
                    dotLocation += 3;
                }
                tocPage.Canvas.DrawString(pageNumText, titlesFont, PdfBrushes.CadetBlue, pageNumlocation, y);

                //為目錄頁中的文本添加可點擊的跳轉(zhuǎn)動作
                location = new PointF(0, y);
                RectangleF titleBounds = new RectangleF(location, new SizeF(tocPage.Canvas.ClientSize.Width, titleSize.Height));
                PdfDestination Dest = new PdfDestination(navigatedPage, new PointF(-doc.PageSettings.Margins.Top, -doc.PageSettings.Margins.Left));
                PdfActionAnnotation action = new PdfActionAnnotation(titleBounds, new PdfGoToAction(Dest));
                action.Border = new PdfAnnotationBorder(0);
                (tocPage as PdfNewPage).Annotations.Add(action);
                y += titleSize.Height + 10;
            }

            //保存生成的 PDF 文檔
            doc.SaveToFile("AddTableOfContents.pdf");
            doc.Close();
        }
    }
}