.NET Word Library - Table of Contents in a Word Document using C#

using Syncfusion.DocIO; 
using Syncfusion.DocIO.DLS; 
using Syncfusion.DocIORenderer; 
//Create a new Word document. 
using WordDocument document = new WordDocument(); 
//Add the TOC in the first section. 
IWSection section = document.AddSection(); 
IWParagraph paragraph = section.AddParagraph(); 
string paraText = "AdventureWorks Cycles, the fictitious company on which the AdventureWorks sample databases are based, is a large, multinational manufacturing company."; 
//Append TOC for heading levels 1 to 3. 
paragraph.AppendTOC(1, 3); 
//Add the first chapter. 
section = document.AddSection(); 
paragraph = section.AddParagraph(); 
paragraph.AppendText("First Chapter"); 
paragraph.ApplyStyle(BuiltinStyle.Heading1); 
section.AddParagraph().AppendText(paraText); 
//Add the second chapter. 
section = document.AddSection(); 
paragraph = section.AddParagraph(); 
paragraph.AppendText("Second Chapter"); 
paragraph.ApplyStyle(BuiltinStyle.Heading2); 
section.AddParagraph().AppendText(paraText); 
//Add the third chapter. 
section = document.AddSection(); 
paragraph = section.AddParagraph(); 
paragraph.AppendText("Third Chapter"); 
paragraph.ApplyStyle(BuiltinStyle.Heading3); 
section.AddParagraph().AppendText(paraText); 
//Update the table of contents. 
document.UpdateTableOfContents(); 
//Save the Word document. 
using FileStream outputFileStream = new FileStream("Result.docx", FileMode.Create, FileAccess.ReadWrite); 
document.Save(outputFileStream, FormatType.Docx);