Group wise data in new iText7 PDF page in ASP.Net

Hi comunidadmexi...,

Loop through the DataTable rows and check the columns with condition.

Refer below modified code.

string filename;
string html;
string dest;
Paragraph contents;
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[]
        {
            new DataColumn("sID"),
            new DataColumn("sUnity"),
            new DataColumn("contents")
        });
        dt.Rows.Add(83, "Q400", "Set n.1");
        dt.Rows.Add(84, "Q400", "- Par 1.1");
        dt.Rows.Add(85, "Q400", "<b>bold text</b>");
        dt.Rows.Add(86, "Q400", "- Par 1.2");
        dt.Rows.Add(87, "Q400", "normal text");
        dt.Rows.Add(88, "Q400", "Set n.2");
        dt.Rows.Add(89, "Q400", "- Par 2.1");
        dt.Rows.Add(90, "Q400", "<i>italic text</i>");
        dt.Rows.Add(91, "Q400", "- Par 2.2");
        dt.Rows.Add(92, "Q400", "<u>underline text</u>");
        dt.Rows.Add(93, "Q400", "- Par 2.3");

        filename = @"C:\Users\developer4\Desktop\Management_" + Guid.NewGuid() + ".pdf";
        PdfWriter writer = new PdfWriter(filename);
        PdfDocument pdf = new PdfDocument(writer);
        Document document = new Document(pdf);

        if (dt.Rows.Count > 0)
        {
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                contents = new Paragraph(dt.Rows[i]["contents"].ToString())
                            .SetTextAlignment(TextAlignment.JUSTIFIED).SetFontSize(12);
                if (dt.Rows[i]["contents"].ToString().StartsWith("Set ") && i != 0)
                {
                    document.Add(new AreaBreak(AreaBreakType.NEXT_PAGE));
                }
                IElement lst = HtmlConverter.ConvertToElements(dt.Rows[i]["contents"].ToString()).FirstOrDefault();

                IBlockElement element = (IBlockElement)lst;
                if (dt.Rows[i]["contents"].ToString().StartsWith("Set"))
                {
                    contents.SetFontSize(12)
                        .SetBold()
                        .SetFontColor(ColorConstants.BLUE);
                }
                else if (dt.Rows[i]["contents"].ToString().StartsWith("- "))
                {
                    contents.SetFontSize(11)
                        .SetBold()
                        .SetFontColor(ColorConstants.BLACK);
                }
                else
                {
                    contents.SetTextAlignment(TextAlignment.JUSTIFIED_ALL)
                        .SetFontSize(10)
                        .SetFontColor(ColorConstants.BLACK);

                }
                document.Add(element);
            }

            dest = filename.ToString();
        }
        else
        {
            Console.WriteLine("No rows found.");
        }
        document.Close();

        Response.Clear();
        Response.ContentType = "application/pdf";
        Response.AppendHeader("Content-Disposition", "attachment; filename=" + dest);
        Response.TransmitFile(dest);
        Response.End();
    }
}