Modify Bookmarks in Existing PDF in C#/VB.NET

In order to distinguish nested bookmarks more clearly, you can set different font style and font color for parent and child bookmarks respectively. In this article, I’ll introduce how to modify bookmarks in the terms of font style, font color and text using Spire.PDF in C#, VB.NET.

Main Steps:

Step 1: Initialize a new object of PdfDocument and load the existing PDF file.

PdfDocument doc = new PdfDocument("Bookmark.Pdf");

Step 2: Get all bookmarks from the test file.

PdfBookmarkCollection bookmarks = doc.Bookmarks;

Step 3: Traverse very first-level bookmark in the bookmark tree. Change the properties of selected or all bookmarks, including title, color and display style.

foreach (PdfBookmark parentBookmark in bookmarks)
{
    //change "Word Bookmarks" to "M BookMark"
    bookmarks[0].Title = "Modified BookMarks";      
    //set the color of the bookmark
    parentBookmark.Color = Color.Black;
    parentBookmark.DisplayStyle = PdfTextStyle.Bold;
    //edit child bookmark of parent bookmark
    EditChildBookmark(parentBookmark);
}

Step 4: In step 3, there is a nested method predefined as below. By invoking this method, we are able to modify child bookmarks of the upper level bookmark. In this example, we have two nested level bookmarks under the first-level bookmark.

static void EditChildBookmark(PdfBookmark parentBookmark)
{
   foreach (PdfBookmark childBookmark in parentBookmark)
   {
        childBookmark.Color = Color.Brown;
        childBookmark.DisplayStyle = PdfTextStyle.Regular;
        EditChild2Bookmark(childBookmark);
    }
}
static void EditChild2Bookmark(PdfBookmark childBookmark)
{
    foreach (PdfBookmark child2Bookmark in childBookmark)
    {           
        child2Bookmark.Color = Color.LightSalmon;
        child2Bookmark.DisplayStyle = PdfTextStyle.Italic; 
    }
}

Step 5: Save and launch the file.

doc.SaveToFile("Result.Pdf");
System.Diagnostics.Process.Start("Result.Pdf");

Screenshot of Effect:

How to Modify Bookmarks in Existing PDF in C#, VB.NET

Entire Code:

[C#]

using Spire.Pdf;
using Spire.Pdf.Bookmarks;
using System.Drawing;


namespace ModifyBookmarks
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfDocument doc = new PdfDocument("Bookmark.Pdf");
            PdfBookmarkCollection bookmarks = doc.Bookmarks;
            foreach (PdfBookmark parentBookmark in bookmarks)
            {
                //change "Word Bookmarks" to "M BookMark"
                bookmarks[0].Title = "Modified BookMarks";
                //set the color of the bookmark
                parentBookmark.Color = Color.Black;
                parentBookmark.DisplayStyle = PdfTextStyle.Bold;
                //edit child bookmark of parent bookmark
                EditChildBookmark(parentBookmark);
            }
            doc.SaveToFile("Result.Pdf");
            System.Diagnostics.Process.Start("Result.Pdf");
        }
        static void EditChildBookmark(PdfBookmark parentBookmark)
        {
            foreach (PdfBookmark childBookmark in parentBookmark)
            {
                childBookmark.Color = Color.Brown;
                childBookmark.DisplayStyle = PdfTextStyle.Regular;
                EditChild2Bookmark(childBookmark);
            }
        }
        static void EditChild2Bookmark(PdfBookmark childBookmark)
        {
            foreach (PdfBookmark child2Bookmark in childBookmark)
            {
                child2Bookmark.Color = Color.LightSalmon;
                child2Bookmark.DisplayStyle = PdfTextStyle.Italic;
            }
        }
    }
}

[VB.NET]

Imports Spire.Pdf
Imports Spire.Pdf.Bookmarks
Imports System.Drawing


Namespace ModifyBookmarks
	Class Program
		Private Shared Sub Main(args As String())
			Dim doc As New PdfDocument("Bookmark.Pdf")
			Dim bookmarks As PdfBookmarkCollection = doc.Bookmarks
			For Each parentBookmark As PdfBookmark In bookmarks
				'change "Word Bookmarks" to "M BookMark"
				bookmarks(0).Title = "Modified BookMarks"
				'set the color of the bookmark
				parentBookmark.Color = Color.Black
				parentBookmark.DisplayStyle = PdfTextStyle.Bold
				'edit child bookmark of parent bookmark
				EditChildBookmark(parentBookmark)
			Next
			doc.SaveToFile("Result.Pdf")
			System.Diagnostics.Process.Start("Result.Pdf")
		End Sub
		Private Shared Sub EditChildBookmark(parentBookmark As PdfBookmark)
			For Each childBookmark As PdfBookmark In parentBookmark
				childBookmark.Color = Color.Brown
				childBookmark.DisplayStyle = PdfTextStyle.Regular
				EditChild2Bookmark(childBookmark)
			Next
		End Sub
		Private Shared Sub EditChild2Bookmark(childBookmark As PdfBookmark)
			For Each child2Bookmark As PdfBookmark In childBookmark
				child2Bookmark.Color = Color.LightSalmon
				child2Bookmark.DisplayStyle = PdfTextStyle.Italic
			Next
		End Sub
	End Class
End Namespace

Modify Bookmarks in Existing PDF in C#/VB.NET

See Also