使用iTextSharp VS2017 c#以编程方式从大纲中删除pdf书签

using iTextSharp.text;
using iTextSharp.text.pdf;

string filePath = "path_to_pdf_file";
PdfReader reader = new PdfReader(filePath);

PdfOutline rootOutline = reader.Outlines;

foreach (PdfOutline outline in rootOutline.AllChildren) {
    outline.Remove();
}

string outputFilePath = "path_to_output_pdf_file";
PdfStamper stamper = new PdfStamper(reader, new FileStream(outputFilePath, FileMode.Create));
stamper.Close();
reader.Close();