页定位自动增加书签

public class BookMarkHelper : PdfPageEventHelper

{

    private int currentPageNum;

    private List<int> pageNumList = new List<int>();

    private List<string> titleList = new List<string>();//中文标签也不用指定字体

    public void Add(string title)//需要在什么地方加标签就调用一下，title书签名

    {

        titleList.Add(title);

        pageNumList.Add(currentPageNum + 1);//页以0开始

    }

    public override void OnEndPage(PdfWriter writer, Document document)

    {

        currentPageNum = writer.PageNumber;

    }

    public void AddToPdf(PdfWriter writer)

    {        

        //书签树的根

        var root = writer.DirectContent.RootOutline;

        for (int i = 0; i < pageNumList.Count; i++)

        {

            var action = PdfAction.GotoLocalPage(pageNumList[i], new PdfDestination(PdfDestination.FIT), writer);

            var outLine = new PdfOutline(root, action, titleList[i]);

        }

    }

}

Uasage:var pdfWriter = PdfWriter.GetInstance(document, pdfMemoryStream);

            //pdfWriter.ViewerPreferences = PdfWriter.PageModeUseOutlines; //打开时显示书签

 var bookMarkHelper = new BookMarkHelper();

 pdfWriter.PageEvent = bookMarkHelper; 

 document.Open();

 document.Add(Paragraph).................

 bookMarkHelper.Add("书签一");

document.Add(Paragraph).................

 bookMarkHelper.Add("书签二");

document.Add(Paragraph).................

bookMarkHelper.AddToPdf(pdfWriter);//这时候才加入书签