public static Font GetTahoma()
    {
        var fontName = "Tahoma";
        if (!FontFactory.IsRegistered(fontName))
        {
            var fontPath = Environment.GetEnvironmentVariable("SystemRoot") + "\\fonts\\tahoma.ttf";
            FontFactory.Register(fontPath);
        }
        return FontFactory.GetFont(fontName, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
    }
 

 string fileNameExisting = @"Test.pdf";
        string fileNameNew = @"newform.pdf";
         using (var existingFileStream = new FileStream(fileNameExisting, FileMode.Open))
            using (var newFileStream = new FileStream(fileNameNew, FileMode.Create))
            {
                var pdfReader = new PdfReader(existingFileStream);
                using (var stamper = new PdfStamper(pdfReader, newFileStream))
                {
                    //نکته مهم جهت کار با اطلاعات فارسی
                    //در غیراینصورت شاهد ثبت اطلاعات نخواهید بود
                    stamper.AcroFields.AddSubstitutionFont(GetTahoma().BaseFont);
 
                    //form.Fields.Keys = تمام فیلدهای موجود در فرم
                    var form = stamper.AcroFields;                  
 
                    //مقدار دهی فیلدهای فرم
                    form.SetField("Text1", "مقدار1");
                     form.SetField("Text2", "مقدار2");
                     form.SetField("Text3", "مقدار3");
                     form.SetField("Text4", "مقدار4");
                     form.SetField("Text5", "مقدار5");
                     form.SetField("Text6", "مقدار6");
                   
 
                   
                    // به این ترتیب فرم دیگر توسط کاربر قابل ویرایش نخواهد بود
                    //stamper.PartialFormFlattening --> جهت غیرقابل ویرایش نمودن فیلدی مشخص
                    stamper.FormFlattening = true;
 
                    stamper.Close();
                    pdfReader.Close();
                }
            }
 
            Process.Start("newform.pdf");

using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace OptimizeImageSizes
{
    class Program
    {
        static void Main(string[] args)
        {
            test1();
            test2();
        }

        private static void test2()
        {
            using (var pdfDoc = new Document(PageSize.A4))
            {
                var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test2.pdf", FileMode.Create));
                pdfDoc.Open();

                var table = new PdfPTable(new float[] { 1, 2 });
                table.AddCell(Image.GetInstance("myImage.png"));
                table.AddCell(Image.GetInstance("myImage.png"));
                pdfDoc.Add(table);
            }

            Process.Start("test2.pdf");
        }

        private static void test1()
        {
            using (var pdfDoc = new Document(PageSize.A4))
            {
                var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test1.pdf", FileMode.Create));
                pdfDoc.Open();

                var table = new PdfPTable(new float[] { 1, 2 });                
                var image = Image.GetInstance("myImage.png");
                table.AddCell(image);
                table.AddCell(image);
                pdfDoc.Add(table);
            }

            Process.Start("test1.pdf");
        }
    }
}

   public iTextSharp.text.Font GetBNazanin()
        {

            var fontName = "BNazanin";
            var fontPath = Path.Combine(_hostingEnvironment.WebRootPath + @"\css\font\BNazanin\BNazanin.ttf");

            if (!FontFactory.IsRegistered(fontName))// به درستی کار می‌کند و در صورت وجود از کش می‌خواند
            {
                FontFactory.Register(fontPath);
            }

            return FontFactory.GetFont(fontPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
        }

  public iTextSharp.text.Font GetIRANSans()
        {
            var fontName = "IRANSansWeb(FaNum)_Medium";
            var fontPath = Path.Combine(_hostingEnvironment.WebRootPath + @"\css\font\IRANSansWeb(FaNum)_Medium.ttf");
          
            if (!FontFactory.IsRegistered(fontName))// always false
            {
                FontFactory.Register(fontPath);
            }
            return FontFactory.GetFont(fontPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
        }

using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace PDFAttachment
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var pdfDoc = new Document(PageSize.A4))
            {
                var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));                
                pdfDoc.Open();

                pdfDoc.Add(new Phrase("Test"));

                var fs = PdfFileSpecification.FileEmbedded(pdfWriter, @"C:\path\logo.png", "logo.png", null);
                pdfWriter.AddFileAttachment("توضیحات",fs);
            }

            Process.Start("Test.pdf");
        }
    }
}

• قسمت modified مقدار دهی نشده است.
• پنل مربوط به پیوست‌ها باید دستی باز شود.

using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace PDFAttachment
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var pdfDoc = new Document(PageSize.A4))
            {
                var pdfWriter = PdfWriter.GetInstance(pdfDoc, new FileStream("Test.pdf", FileMode.Create));                
                pdfDoc.Open();

                pdfDoc.Add(new Phrase("Test"));

                var filePath = @"C:\path\logo.png";
                var fileInfo = new FileInfo(filePath);
                var pdfDictionary = new PdfDictionary();
                pdfDictionary.Put(PdfName.MODDATE, new PdfDate(fileInfo.LastWriteTime));
                var fs = PdfFileSpecification.FileEmbedded(pdfWriter, filePath, fileInfo.Name, null, true, null, pdfDictionary);
                pdfWriter.AddFileAttachment("توضیحات", fs);
            }

            Process.Start("Test.pdf");
        }
    }
}

pdfWriter.ViewerPreferences = PdfWriter.PageModeUseAttachments;

using System.Diagnostics;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace PDFAttachment
{
    class Program
    {
        static void Main(string[] args)
        {
            var reader = new PdfReader("Test.pdf");
            using (var stamper = new PdfStamper(reader, new FileStream("newTest.pdf", FileMode.Create)))
            {
                var filePath = @"C:\path\logo.png";
                addAttachment(stamper, filePath, "توضیحات");
                stamper.Close();
            }

            Process.Start("newTest.pdf");
        }

        private static void addAttachment(PdfStamper stamper, string filePath, string description)
        {
            var fileInfo = new FileInfo(filePath);
            var pdfDictionary = new PdfDictionary();
            pdfDictionary.Put(PdfName.MODDATE, new PdfDate(fileInfo.LastWriteTime));
            var pdfWriter = stamper.Writer;
            var fs = PdfFileSpecification.FileEmbedded(pdfWriter, filePath, fileInfo.Name, null, true, null, pdfDictionary);
            stamper.AddFileAttachment(description, fs);
        }
    }
}

namespace PdfReportSamples.Models
{
    public class Task
    {
        public int Id { set; get; }
        public string Name { set; get; }
        public int PercentCompleted { set; get; }
        public bool IsActive { set; get; }
        public User Assignee { set; get; }
    }
}

using System;

namespace PdfReportSamples.Models
{
    public class User
    {
        public int Id { set; get; }
        public string Name { set; get; }
        public string LastName { set; get; }
        public long Balance { set; get; }
        public DateTime RegisterDate { set; get; }
    }
}

 column.PropertyName<Task>(x => x.Assignee.Name) 

using System;
using System.Collections.Generic;
using System.Drawing;
using PdfReportSamples.Models;
using PdfRpt.Core.Contracts;
using PdfRpt.FluentInterface;

namespace PdfReportSamples.CustomHeaderFooter
{
    public class CustomHeaderFooterPdfReport
    {
        readonly CustomHeader _customHeader = new CustomHeader();
        public IPdfReportData CreatePdfReport()
        {
            return new PdfReport().DocumentPreferences(doc =>
            {
                doc.RunDirection(PdfRunDirection.LeftToRight);
                doc.Orientation(PageOrientation.Portrait);
                doc.PageSize(PdfPageSize.A4);
                doc.DocumentMetadata(new DocumentMetadata { Author = "Vahid", Application = "PdfRpt", Keywords = "Test", Subject = "Test Rpt", Title = "Test" });
            })
            .DefaultFonts(fonts =>
            {
                fonts.Path(Environment.GetEnvironmentVariable("SystemRoot") + "\\fonts\\tahoma.ttf",
                                  Environment.GetEnvironmentVariable("SystemRoot") + "\\fonts\\verdana.ttf");
            })
            .PagesFooter(footer =>
            {
                footer.CustomFooter(new CustomFooter(footer.PdfFont, PdfRunDirection.LeftToRight));
            })
            .PagesHeader(header =>
            {
                header.CustomHeader(_customHeader);
            })
            .MainTableTemplate(template =>
            {
                template.BasicTemplate(BasicTemplate.SilverTemplate);
            })
            .MainTablePreferences(table =>
            {
                table.ColumnsWidthsType(TableColumnWidthType.Relative);
                table.MultipleColumnsPerPage(new MultipleColumnsPerPage
                {
                    ColumnsGap = 22,
                    ColumnsPerPage = 2,
                    ColumnsWidth = 250,
                    IsRightToLeft = false,
                    TopMargin = 7
                });
            })
            .MainTableDataSource(dataSource =>
            {
                var rows = new List<Task>();
                var rnd = new Random();
                for (int i = 1; i < 210; i++)
                {
                    rows.Add(new Task
                    {
                        Assignee = new User
                        {
                            Id = i,
                            Name = "user-" + i
                        },
                        IsActive = rnd.Next(0, 2) == 1 ? true : false,
                        Name = "task-" + i
                    });
                }
                dataSource.StronglyTypedList(rows);
            })
            .MainTableColumns(columns =>
            {
                columns.AddColumn(column =>
                {
                    column.PropertyName("rowNo");
                    column.IsRowNumber(true);
                    column.CellsHorizontalAlignment(HorizontalAlignment.Center);
                    column.IsVisible(true);
                    column.Order(0);
                    column.Width(1);
                    column.HeaderCell("#");
                });

                columns.AddColumn(column =>
                {
                    column.PropertyName<Task>(x => x.Name);
                    column.CellsHorizontalAlignment(HorizontalAlignment.Center);
                    column.IsVisible(true);
                    column.Order(1);
                    column.Width(3);
                    column.HeaderCell("Task Name");
                });

                columns.AddColumn(column =>
                {
                    column.PropertyName<Task>(x => x.Assignee.Name); // nested property support
                    column.CellsHorizontalAlignment(HorizontalAlignment.Center);
                    column.IsVisible(true);
                    column.Order(2);
                    column.Width(3);
                    column.HeaderCell("Assignee");
                });

                columns.AddColumn(column =>
                {
                    column.PropertyName<Task>(x => x.IsActive);
                    column.CellsHorizontalAlignment(HorizontalAlignment.Center);
                    column.IsVisible(true);
                    column.Order(3);
                    column.Width(2);
                    column.HeaderCell("Active");
                    column.ColumnItemsTemplate(template =>
                    {
                        template.Checkmark(checkmarkFillColor: Color.Green, crossSignFillColor: Color.DarkRed);
                    });
                });
            })
            .MainTableEvents(events =>
            {
                events.DataSourceIsEmpty(message: "There is no data available to display.");
            })
            .Export(export =>
            {
                export.ToExcel();
            })
            .Generate(data => data.AsPdfFile(AppPath.ApplicationPath + "\\Pdf\\CustomHeaderFooterPdfReportSample.pdf"));
        }
    }
}

using System.Collections.Generic;
using iTextSharp.text;
using iTextSharp.text.pdf;
using PdfRpt.Core.Contracts;
using PdfRpt.Core.Helper;

namespace PdfReportSamples.CustomHeaderFooter
{
    public class CustomHeader : IPageHeader
    {
        public PdfPTable RenderingGroupHeader(Document pdfDoc, PdfWriter pdfWriter, IList<CellData> rowdata, IList<SummaryCellData> summaryData)
        {
            return null;
        }

        Image _image;
        public PdfPTable RenderingReportHeader(Document pdfDoc, PdfWriter pdfWriter, IList<SummaryCellData> summaryData)
        {
            if (_image == null) //cache is empty
            {
                var templatePath = AppPath.ApplicationPath + "\\data\\PdfHeaderTemplate.pdf";
                _image = PdfImageHelper.GetITextSharpImageFromPdfTemplate(pdfWriter, templatePath);
            }

            var table = new PdfPTable(1);
            var cell = new PdfPCell(_image, true) { Border = 0 };
            table.AddCell(cell);
            return table;
        }
    }
}

using System.Collections.Generic;
using iTextSharp.text;
using iTextSharp.text.pdf;
using PdfRpt.Core.Contracts;

namespace PdfReportSamples.CustomHeaderFooter
{
    public class CustomFooter : IPageFooter
    {
        PdfContentByte _pdfContentByte;
        readonly IPdfFont _pdfRptFont;
        readonly Font _font;
        readonly PdfRunDirection _direction;
        PdfTemplate _template;

        public CustomFooter(IPdfFont pdfRptFont, PdfRunDirection direction)
        {
            _direction = direction;
            _pdfRptFont = pdfRptFont;
            _font = _pdfRptFont.Fonts[0];
        }

        public void ClosingDocument(PdfWriter writer, Document document, IList<SummaryCellData> columnCellsSummaryData)
        {
            _template.BeginText();
            _template.SetFontAndSize(_pdfRptFont.Fonts[0].BaseFont, 8);
            _template.SetTextMatrix(0, 0);
            _template.ShowText((writer.PageNumber - 1).ToString());
            _template.EndText();
        }

        public void PageFinished(PdfWriter writer, Document document, IList<SummaryCellData> columnCellsSummaryData)
        {
            var pageSize = document.PageSize;
            var text = "Page " + writer.PageNumber + " / ";
            var textLen = _font.BaseFont.GetWidthPoint(text, _font.Size);
            var center = (pageSize.Left + pageSize.Right) / 2;
            var align = _direction == PdfRunDirection.RightToLeft ? Element.ALIGN_RIGHT : Element.ALIGN_LEFT;

            ColumnText.ShowTextAligned(
                        canvas: _pdfContentByte,
                        alignment: align,
                        phrase: new Phrase(text, _font),
                        x: center,
                        y: pageSize.GetBottom(25),
                        rotation: 0,
                        runDirection: (int)_direction,
                        arabicOptions: 0);

            var x = _direction == PdfRunDirection.RightToLeft ? center - textLen : center + textLen;
            _pdfContentByte.AddTemplate(_template, x, pageSize.GetBottom(25));
        }

        public void DocumentOpened(PdfWriter writer, IList<SummaryCellData> columnCellsSummaryData)
        {
            _pdfContentByte = writer.DirectContent;
            _template = _pdfContentByte.CreateTemplate(50, 50);
        }
    }
}

using System.Collections.Generic;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace PdfRpt.Core.Contracts
{
    public interface IPageHeader
    {
        PdfPTable RenderingGroupHeader(Document pdfDoc, PdfWriter pdfWriter, IList<CellData> newGroupInfo, IList<SummaryCellData> summaryData);

        PdfPTable RenderingReportHeader(Document pdfDoc, PdfWriter pdfWriter, IList<SummaryCellData> summaryData);
    }
}

using iTextSharp.text;
using iTextSharp.text.pdf;
using System.Collections.Generic;

namespace PdfRpt.Core.Contracts
{
    public interface IPageFooter
    {
        void DocumentOpened(PdfWriter writer, IList<SummaryCellData> columnCellsSummaryData);

        void PageFinished(PdfWriter writer, Document document, IList<SummaryCellData> columnCellsSummaryData);

        void ClosingDocument(PdfWriter writer, Document document, IList<SummaryCellData> columnCellsSummaryData);
    }
}

readonly CustomHeader _customHeader = new CustomHeader();
//...
.PagesFooter(footer =>
{
   footer.CustomFooter(new CustomFooter(footer.PdfFont, PdfRunDirection.LeftToRight));
})
.PagesHeader(header =>
{
  header.CustomHeader(_customHeader);
})