The sample demonstrates how to Set bookmark in Word document.

private void button1_Click(object sender, EventArgs e)
{
    //Create word document
    Document document = new Document();

    Bookmark(document.AddSection());

    //Save doc file.
    document.SaveToFile("Sample.doc",FileFormat.Doc);

    //Launching the MS Word file.
    WordDocViewer("Sample.doc");


}

private void Bookmark(Section section)
{
    Paragraph paragraph = section.AddParagraph();
    paragraph.AppendText("The sample demonstrates how to using bookmark.");
    paragraph.ApplyStyle(BuiltinStyle.Heading2);

    section.AddParagraph();
    paragraph = section.AddParagraph();
    paragraph.AppendText("Simple bookmark.");
    paragraph.ApplyStyle(BuiltinStyle.Heading4);
    
    // Writing simple bookmarks
    section.AddParagraph();
    paragraph = section.AddParagraph();
    paragraph.AppendBookmarkStart("SimpleBookMark");
    paragraph.AppendText("This is a simple book mark.");
    paragraph.AppendBookmarkEnd("SimpleBookMark");

    section.AddParagraph();
    paragraph = section.AddParagraph();
    paragraph.AppendText("Nested bookmark.");
    paragraph.ApplyStyle(BuiltinStyle.Heading4);

    // Writing nested bookmarks
    section.AddParagraph();
    paragraph = section.AddParagraph();
    paragraph.AppendBookmarkStart("Root");
    paragraph.AppendText(" Root data ");
    paragraph.AppendBookmarkStart("NestedLevel1");
    paragraph.AppendText(" Nested Level1 ");
    paragraph.AppendBookmarkStart("NestedLevel2");
    paragraph.AppendText(" Nested Level2 ");
    paragraph.AppendBookmarkEnd("NestedLevel2");
    paragraph.AppendText(" Data Level1 ");
    paragraph.AppendBookmarkEnd("NestedLevel1");
    paragraph.AppendText(" Data Root ");
    paragraph.AppendBookmarkEnd("Root");

}

private void WordDocViewer(string fileName)
{
    try
    {
        System.Diagnostics.Process.Start(fileName);
    }
    catch { }
}

Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
	'Create word document
	Dim document_Renamed As New Document()

	Bookmark(document_Renamed.AddSection())

	'Save doc file.
	document_Renamed.SaveToFile("Sample.doc",FileFormat.Doc)

	'Launching the MS Word file.
	WordDocViewer("Sample.doc")


End Sub

Private Sub Bookmark(ByVal section_Renamed As Section)
	Dim paragraph_Renamed As Paragraph = section_Renamed.AddParagraph()
	paragraph_Renamed.AppendText("The sample demonstrates how to using bookmark.")
	paragraph_Renamed.ApplyStyle(BuiltinStyle.Heading2)

	section_Renamed.AddParagraph()
	paragraph_Renamed = section_Renamed.AddParagraph()
	paragraph_Renamed.AppendText("Simple bookmark.")
	paragraph_Renamed.ApplyStyle(BuiltinStyle.Heading4)

	' Writing simple bookmarks
	section_Renamed.AddParagraph()
	paragraph_Renamed = section_Renamed.AddParagraph()
	paragraph_Renamed.AppendBookmarkStart("SimpleBookMark")
	paragraph_Renamed.AppendText("This is a simple book mark.")
	paragraph_Renamed.AppendBookmarkEnd("SimpleBookMark")

	section_Renamed.AddParagraph()
	paragraph_Renamed = section_Renamed.AddParagraph()
	paragraph_Renamed.AppendText("Nested bookmark.")
	paragraph_Renamed.ApplyStyle(BuiltinStyle.Heading4)

	' Writing nested bookmarks
	section_Renamed.AddParagraph()
	paragraph_Renamed = section_Renamed.AddParagraph()
	paragraph_Renamed.AppendBookmarkStart("Root")
	paragraph_Renamed.AppendText(" Root data ")
	paragraph_Renamed.AppendBookmarkStart("NestedLevel1")
	paragraph_Renamed.AppendText(" Nested Level1 ")
	paragraph_Renamed.AppendBookmarkStart("NestedLevel2")
	paragraph_Renamed.AppendText(" Nested Level2 ")
	paragraph_Renamed.AppendBookmarkEnd("NestedLevel2")
	paragraph_Renamed.AppendText(" Data Level1 ")
	paragraph_Renamed.AppendBookmarkEnd("NestedLevel1")
	paragraph_Renamed.AppendText(" Data Root ")
	paragraph_Renamed.AppendBookmarkEnd("Root")

End Sub

Private Sub WordDocViewer(ByVal fileName As String)
	Try
		Process.Start(fileName)
	Catch
	End Try
End Sub

The sample demonstrates how to set text style in Word document.

private void button1_Click(object sender, EventArgs e)
{
    //Create word document
    Document document = new Document();

    //Create a new secition
    Section section = document.AddSection();

    //Create a new paragraph
    Paragraph paragraph = section.AddParagraph();

    //Append Text
    paragraph.AppendText("The various ways to format paragraph text in Microsoft Word:");

    paragraph.ApplyStyle(BuiltinStyle.Heading1);

    //Append alignment text
    AppendAligmentText(section);

    //Append indentation text
    AppendIndentationText(section);

    AppendBulletedList(section);

    //Save doc file.
    document.SaveToFile("Sample.doc",FileFormat.Doc);

    //Launching the MS Word file.
    WordDocViewer("Sample.doc");


}

private void AppendAligmentText(Section section)
{
    Paragraph paragraph = null;

    paragraph = section.AddParagraph();

    //Append Text
    paragraph.AppendText("Horizontal Aligenment");

    paragraph.ApplyStyle(BuiltinStyle.Heading3);

    foreach (Spire.Doc.Documents.HorizontalAlignment align in Enum.GetValues(typeof(Spire.Doc.Documents.HorizontalAlignment)))
    {
        Paragraph paramgraph = section.AddParagraph();
        paramgraph.AppendText("This text is " + align.ToString());
        paramgraph.Format.HorizontalAlignment = align;
    }
}

private void AppendIndentationText(Section section)
{
    Paragraph paragraph = null;

    paragraph = section.AddParagraph();

    //Append Text
    paragraph.AppendText("Indentation");

    paragraph.ApplyStyle(BuiltinStyle.Heading3);

    paragraph = section.AddParagraph();
    paragraph.AppendText("Indentation is the spacing between text and margins. Word allows you to set left and right margins, as well as indentations for the first line of a paragraph and hanging indents");
    paragraph.Format.FirstLineIndent = 15;
}

private void AppendBulletedList(Section section)
{
    Paragraph paragraph = null;

    paragraph = section.AddParagraph();
    

    //Append Text
    paragraph.AppendText("Bulleted List");

    paragraph.ApplyStyle(BuiltinStyle.Heading3);

    paragraph = section.AddParagraph();
    for (int i = 0; i < 5; i++)
    {
        paragraph = section.AddParagraph();
        paragraph.AppendText("Item" + i.ToString());

        if (i == 0)
        {
            paragraph.ListFormat.ApplyBulletStyle();
        }
        else
        {
            paragraph.ListFormat.ContinueListNumbering();
        }

        paragraph.ListFormat.ListLevelNumber = 1;
    }
}





private void WordDocViewer(string fileName)
{
    try
    {
        System.Diagnostics.Process.Start(fileName);
    }
    catch { }
}

Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
	'Create word document
	Dim document_Renamed As New Document()

	'Create a new secition
	Dim section_Renamed As Section = document_Renamed.AddSection()

	'Create a new paragraph
	Dim paragraph_Renamed As Paragraph = section_Renamed.AddParagraph()

	'Append Text
	paragraph_Renamed.AppendText("The various ways to format paragraph text in Microsoft Word:")

	paragraph_Renamed.ApplyStyle(BuiltinStyle.Heading1)

	'Append alignment text
	AppendAligmentText(section_Renamed)

	'Append indentation text
	AppendIndentationText(section_Renamed)

	AppendBulletedList(section_Renamed)

	'Save doc file.
	document_Renamed.SaveToFile("Sample.doc",FileFormat.Doc)

	'Launching the MS Word file.
	WordDocViewer("Sample.doc")


End Sub

Private Sub AppendAligmentText(ByVal section_Renamed As Section)
	Dim paragraph_Renamed As Paragraph = Nothing

	paragraph_Renamed = section_Renamed.AddParagraph()

	'Append Text
	paragraph_Renamed.AppendText("Horizontal Aligenment")

	paragraph_Renamed.ApplyStyle(BuiltinStyle.Heading3)

	For Each align As Spire.Doc.Documents.HorizontalAlignment In System.Enum.GetValues(GetType(Spire.Doc.Documents.HorizontalAlignment))
		Dim paramgraph As Paragraph = section_Renamed.AddParagraph()
		paramgraph.AppendText("This text is " & align.ToString())
		paramgraph.Format.HorizontalAlignment = align
	Next align
End Sub

Private Sub AppendIndentationText(ByVal section_Renamed As Section)
	Dim paragraph_Renamed As Paragraph = Nothing

	paragraph_Renamed = section_Renamed.AddParagraph()

	'Append Text
	paragraph_Renamed.AppendText("Indentation")

	paragraph_Renamed.ApplyStyle(BuiltinStyle.Heading3)

	paragraph_Renamed = section_Renamed.AddParagraph()
	paragraph_Renamed.AppendText("Indentation is the spacing between text and margins. Word allows you to set left and right margins, as well as indentations for the first line of a paragraph and hanging indents")
	paragraph_Renamed.Format.FirstLineIndent = 15
End Sub

Private Sub AppendBulletedList(ByVal section_Renamed As Section)
	Dim paragraph_Renamed As Paragraph = Nothing

	paragraph_Renamed = section_Renamed.AddParagraph()


	'Append Text
	paragraph_Renamed.AppendText("Bulleted List")

	paragraph_Renamed.ApplyStyle(BuiltinStyle.Heading3)

	paragraph_Renamed = section_Renamed.AddParagraph()
	For i As Integer = 0 To 4
		paragraph_Renamed = section_Renamed.AddParagraph()
		paragraph_Renamed.AppendText("Item" & i.ToString())

		If i = 0 Then
			paragraph_Renamed.ListFormat.ApplyBulletStyle()
		Else
			paragraph_Renamed.ListFormat.ContinueListNumbering()
		End If

		paragraph_Renamed.ListFormat.ListLevelNumber = 1
	Next i
End Sub





Private Sub WordDocViewer(ByVal fileName As String)
	Try
		Process.Start(fileName)
	Catch
	End Try
End Sub

The sample demonstrates how to Set Word styles.

private void button1_Click(object sender, EventArgs e)
{
    //Create word document
    Document document = new Document();

    //Create a new secition
    Section section = document.AddSection();

    //Create a new paragraph
    Paragraph paragraph = section.AddParagraph();

    //Append Text
    paragraph.AppendText("Builtin Style:");

    foreach (BuiltinStyle builtinStyle in Enum.GetValues(typeof(BuiltinStyle)))
    {
        paragraph = section.AddParagraph();
        //Append Text
        paragraph.AppendText(builtinStyle.ToString());
        //Apply Style
        paragraph.ApplyStyle(builtinStyle);
    }

    //Save doc file.
    document.SaveToFile("Sample.doc",FileFormat.Doc);

    //Launching the MS Word file.
    WordDocViewer("Sample.doc");


}

private void WordDocViewer(string fileName)
{
    try
    {
        System.Diagnostics.Process.Start(fileName);
    }
    catch { }
}

Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
	'Create word document
	Dim document_Renamed As New Document()

	'Create a new secition
	Dim section_Renamed As Section = document_Renamed.AddSection()

	'Create a new paragraph
	Dim paragraph_Renamed As Paragraph = section_Renamed.AddParagraph()

	'Append Text
	paragraph_Renamed.AppendText("Builtin Style:")

	For Each builtinStyle_Renamed As BuiltinStyle In System.Enum.GetValues(GetType(BuiltinStyle))
		paragraph_Renamed = section_Renamed.AddParagraph()
		'Append Text
		paragraph_Renamed.AppendText(builtinStyle_Renamed.ToString())
		'Apply Style
		paragraph_Renamed.ApplyStyle(builtinStyle_Renamed)
	Next builtinStyle_Renamed

	'Save doc file.
	document_Renamed.SaveToFile("Sample.doc",FileFormat.Doc)

	'Launching the MS Word file.
	WordDocViewer("Sample.doc")


End Sub

Private Sub WordDocViewer(ByVal fileName As String)
	Try
		Process.Start(fileName)
	Catch
	End Try
End Sub