How to print long page with multiple pages as PDF

using System.Windows.Forms;

using iTextSharp.text.pdf;

using iTextSharp.text;

namespace ActiveTest

{

    public partial class Test : Page

    {

        protected override void OnLoad(EventArgs e)

        {

            base.OnLoad(e);

            string mode = this.Request.QueryString.Get("mode");

            string page = this.Request.QueryString.Get("page");

            if (!string.IsNullOrEmpty(mode) && mode.Equals("Print"))

            {

                int p = int.Parse(page);

                ///

                /// bind relevent page of the gridview

                /// 

                Response.Write("This is page " + page);

            }

        }

        protected void PrintPDF(object sender, EventArgs e)

        {

            int listId = 12345;

            ///

            /// A4 Size:

            ///

            int width = 595;

            int height = 792;

            int leftMargin = 20;

            int rightMargin = 20;

            iTextSharp.text.Rectangle pgSize = new iTextSharp.text.Rectangle(width, height);

            Document doc = new Document(pgSize, leftMargin, rightMargin, 48, 24);

            string f = Server.MapPath(string.Format("~/Temp/{0}.pdf", listId));

            PdfWriter.GetInstance(doc, new FileStream(f, FileMode.Create));

            doc.Open();

            int rowCount = this.GetRowCount();

            int pageSize = 30;

            for (int j = 0; j < (rowCount / pageSize) + 1; j++)

            {

                string url = this.Request.Url.ToString() + "?id=" + listId + "&mode=Print&page=" + j;

                Image thumbnail = new Image(url, width, height, width, height, Image.ImageMethod.Url);

                using (Bitmap image = thumbnail.GenerateImage())

                {

                    iTextSharp.text.Image i = iTextSharp.text.Image.GetInstance(image, 

                                                        System.Drawing.Imaging.ImageFormat.Bmp);

                    doc.Add(i);

                    doc.NewPage();

                }

            }

            doc.Close();

            ///

            /// Use pdf file 

            ///

            File.Delete(f);            

        }

        protected int GetRowCount()

        {

            ///

            /// Get from database.

            ///

            return 130;

        }

    }

    public class Image

    {

        public enum ImageMethod { Url, Html };

        public string Url { get; set; }

        public Bitmap Current { get; set; }

        public int Width { get; set; }

        public int Height { get; set; }

        public int BrowserWidth { get; set; }

        public int BrowserHeight { get; set; }

        public string Html { get; set; }

        public ImageMethod Method { get; set; }

        public Image(string data, int browserWidth, int browserHeight, int width,

                                        int height, ImageMethod method)

        {

            this.Method = method;

            if (method == ImageMethod.Url)

                this.Url = data;

            else if (method == ImageMethod.Html)

                this.Html = data;

            this.BrowserWidth = browserWidth;

            this.BrowserHeight = browserHeight;

            this.Height = height;

            this.Width = width;

        }

        public Bitmap GenerateImage()

        {

            Thread thread = new Thread(new ThreadStart(GenerateThumbnailInteral));

            thread.SetApartmentState(ApartmentState.STA);

            thread.Start();

            thread.Join();

            return Current;

        }

        private void GenerateThumbnailInteral()

        {

            WebBrowser webBrowser = new WebBrowser();

            webBrowser.ScrollBarsEnabled = false;

            if (this.Method == ImageMethod.Url)

                webBrowser.Navigate(this.Url);

            else webBrowser.DocumentText = this.Html;

            webBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(WebBrowser_DocumentCompleted);

            while (webBrowser.ReadyState != WebBrowserReadyState.Complete) Application.DoEvents();

            webBrowser.Dispose();

        }

        private void WebBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)

        {

            WebBrowser webBrowser = (WebBrowser)sender;

            webBrowser.ClientSize = new Size(this.BrowserWidth, this.BrowserHeight);

            webBrowser.ScrollBarsEnabled = false;

            this.Current = new Bitmap(webBrowser.Bounds.Width, webBrowser.Bounds.Height);

            Graphics g = Graphics.FromImage((System.Drawing.Image)this.Current);

            g.InterpolationMode = InterpolationMode.High;

            g.SmoothingMode = SmoothingMode.HighQuality;

            g.Clear(Color.Transparent);

            webBrowser.BringToFront();

            webBrowser.DrawToBitmap(Current, webBrowser.Bounds);

            this.Current = (Bitmap)this.Current.GetThumbnailImage(Width, Height, null, IntPtr.Zero);

            g.Dispose();

        }

    }

}