C#使用iTextSharp获取PDF文件书签信息的操作方法

using iTextSharp.text.pdf;
using System;
using System.Collections.Generic;

// 递归函数，用于获取指定书签下的所有子书签并保持结构
List<Dictionary<string, object>> GetAllSubBookmarks(List<Dictionary<string, object>> bookmarks, string parentTitle)
{
    List<Dictionary<string, object>> result = new List<Dictionary<string, object>>();

    foreach (var bookmark in bookmarks)
    {
        string title = (string)bookmark["Title"];

        if (title == parentTitle)
        {
            if (bookmark.ContainsKey("Kids"))
            {
                List<Dictionary<string, object>> kids = (List<Dictionary<string, object>>)bookmark["Kids"];
                foreach (var subBookmark in kids)
                {
                    Dictionary<string, object> subBookmarkWithChildren = new Dictionary<string, object>();
                    subBookmarkWithChildren["Title"] = subBookmark["Title"];
                    subBookmarkWithChildren["Page"] = subBookmark["Page"];
                    subBookmarkWithChildren["Kids"] = GetAllSubBookmarks(kids, (string)subBookmark["Title"]);

                    result.Add(subBookmarkWithChildren);
                }
            }
        }
    }

    return result;
}

// 加载PDF文件
PdfReader reader = new PdfReader("your_pdf_file_path.pdf");

// 获取PDF的目录信息
List<Dictionary<string, object>> bookmarks = SimpleBookmark.GetBookmark(reader);

// 获取第一个书签下的所有子书签并保持结构
string parentTitle = (string)bookmarks[0]["Title"];
List<Dictionary<string, object>> allSubBookmarks = GetAllSubBookmarks(bookmarks, parentTitle);

// 输出所有子书签
foreach (var subBookmark in allSubBookmarks)
{
    Console.WriteLine("Sub-Title: " + subBookmark["Title"] + ", Page: " + subBookmark["Page"]);
    if (subBookmark.ContainsKey("Kids"))
    {
        foreach (var childBookmark in (List<Dictionary<string, object>>)subBookmark["Kids"])
        {
            Console.WriteLine("  Child Title: " + childBookmark["Title"] + ", Page: " + childBookmark["Page"]);
        }
    }
}

// 关闭PDF阅读器
reader.Close();

/// <summary>
/// 合并多个pdf
/// </summary>
/// <param name="fileList">pdf文件路径集合</param>
/// <param name="outPath">最终pdf的输出目录</param>
/// <param name="width">pdf页宽，mm</param>
/// <param name="height">pdf页高，mm</param>
public static void 合并PDF(List<string> fileList, string outPath, float width, float height) {
    width = (float)(width * 2.83462677);//PDF的mm与实际mm有所区别
    height = (float)(height * 2.83462677);
    iTextSharp.text.pdf.PdfReader reader;
    iTextSharp.text.Document document = new iTextSharp.text.Document(new iTextSharp.text.Rectangle(0, 0, width, height), 0, 0, 0, 0);
    using (FileStream fs = new FileStream(outPath, FileMode.Create)) {
        using (iTextSharp.text.pdf.PdfWriter writer = iTextSharp.text.pdf.PdfWriter.GetInstance(document, fs)) {
            document.Open();
            iTextSharp.text.pdf.PdfContentByte cb = writer.DirectContent;
            iTextSharp.text.pdf.PdfImportedPage newPage;
            for (int i = 0; i < fileList.Count; i++) {
                using (reader = new iTextSharp.text.pdf.PdfReader(fileList[i])) {
                    int iPageNum = reader.NumberOfPages;
                    for (int j = 1; j <= iPageNum; j++) {
                        document.NewPage();
                        newPage = writer.GetImportedPage(reader, j);
                        cb.AddTemplate(newPage, 0, 0);
                    }
                }
            }
            document.Dispose();
        }
    }
}

using iTextSharp.text;  
using iTextSharp.text.pdf;  
  
// 创建一个Document对象  
Document doc = new Document();  
  
// 创建PdfWriter对象，将文档内容写入输出流中  
PdfWriter writer = PdfWriter.GetInstance(doc, new FileStream("output.pdf", FileMode.Create));  
  
// 打开文档进行写入操作  
doc.Open();  
  
// 设置字体和字号  
BaseFont bfChinese = BaseFont.CreateFont(BaseFont.COURIER, BaseFont.WINANSI, BaseFont.EMBEDDED);  
Font bfChineseFont = new Font(bfChinese, 14);  
  
// 创建要添加的段落文本  
string rowInfo = "这是一个测试段落";  
Paragraph paragInfo = new Paragraph(rowInfo, bfChineseFont);  

doc.Add(paragInfo ); // 将写入信息加入到文档中
  
// 获取段落所占的宽度  
// float columnWidth = ColumnText.GetColumnWidth(doc.PageSize.Width, doc.Top, doc.Bottom, paragInfo, Element.ALIGN_LEFT);  
// 计算左右页边距之间的距离  
// float marginDistance = columnWidth / 2; // 假设左右页边距相等，所以取宽度的一半作为距离  
// Console.WriteLine("左右页边距之间的距离: " + marginDistance + "像素");  
  
// 关闭文档流和释放资源  
doc.Close();