Change Bookmark Content While Preserving Formatting using WordsProcessing

Product Version	Product	Author
2025.4.1104	RadWordsProcessing	Yoan Karamanov

Description

This article shows how to change the content of an existing Bookmark in a DOCX document while preserving the original text formatting and character properties using the WordsProcessing library.

Solution

• Import DOCX: Use DocxFormatProvider to read the input DOCX and obtain a RadFlowDocument.
• Initialize editor: Create a RadFlowDocumentEditor for cursor movement and editing.
• Find bookmark: Enumerate BookmarkRangeStart elements and select the bookmark by Name.
• Capture formatting: Get the first Run within the bookmark and copy its CharacterFormatting properties.
• Delete original bookmark content: Delete only the content between the start and end markers while keeping the bookmark structure intact.
• Position cursor: Move the editor back to the start of the bookmark to insert new text in place.
• Copy formatting: Apply the formatting of the original bookmark content to the editor properties.
• Insert text: Add the replacement content.
• Export DOCX: Write the updated document using DocxFormatProvider.

[C#] Replace bookmark content but keep formatting

RadFlowDocument document;
DocxFormatProvider docxFormatProvider = new DocxFormatProvider();

using (Stream input = File.OpenRead("input.docx"))
{
    document = docxFormatProvider.Import(input);
    RadFlowDocumentEditor editor = new RadFlowDocumentEditor(document);

    var documentBookmarks = document.EnumerateChildrenOfType<BookmarkRangeStart>().Select(b => b.Bookmark).ToList();

    // Obtain bookmark by name
    var specificBookmarkByName = documentBookmarks.FirstOrDefault(b => b.Name == "bookmark1");
    // Obtain the first Run element inside the bookmark to copy its formatting
    Run oldBookmarkText = (Run)specificBookmarkByName.BookmarkRangeStart.Paragraph.Inlines.FirstOrDefault(i => i is Run);

    // Keep the bookmark and just change the content
    editor.DeleteContent(specificBookmarkByName.BookmarkRangeStart, specificBookmarkByName.BookmarkRangeEnd, false);
    editor.MoveToInlineEnd(specificBookmarkByName.BookmarkRangeStart);

    // Apply the old formatting to the editor Method 1

    editor.CharacterFormatting.CopyPropertiesFrom(oldBookmarkText.Properties);

    // Apply the old formatting to the editor Method 2

    editor.CharacterFormatting.FontSize.LocalValue = oldBookmarkText.FontSize;
    editor.CharacterFormatting.FontFamily.LocalValue = oldBookmarkText.FontFamily;
    editor.CharacterFormatting.FontStyle.LocalValue = oldBookmarkText.FontStyle;
    editor.CharacterFormatting.FontWeight.LocalValue = oldBookmarkText.FontWeight;
    editor.CharacterFormatting.Strikethrough.LocalValue = oldBookmarkText.Strikethrough;
    editor.CharacterFormatting.FlowDirection.LocalValue = oldBookmarkText.FlowDirection;
    editor.CharacterFormatting.BaselineAlignment.LocalValue = oldBookmarkText.BaselineAlignment;
    editor.CharacterFormatting.ForegroundColor.LocalValue = oldBookmarkText.ForegroundColor;
    editor.CharacterFormatting.HighlightColor.LocalValue = oldBookmarkText.HighlightColor;
    editor.CharacterFormatting.UnderlineColor.LocalValue = oldBookmarkText.Underline.Color;
    editor.CharacterFormatting.UnderlinePattern.LocalValue = oldBookmarkText.Underline.Pattern;

    editor.InsertText("NEW CONTENT");

    using (Stream output = File.OpenWrite("output.docx"))
    {
        docxFormatProvider.Export(document, output);
    }
}

See Also

• Bookmark