(高手！！！！)html转PDF

        public void ProcessRequest(HttpContext context)
        {
            string strurl = MakeUtil.getStringFromRequestByName(context.Request, "URL", -1);
            url = new Uri(strurl.Replace("|", "&"));
            if (url != null)
            {
                this.CreatPdf(context);
            }
            else
            {
                return;
            }
        }        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
        private System.Drawing.Bitmap bitmap;
        private Uri url = null;
        private int w = 760, h = 2393;
        public void setBitmap()
        {
            using (WebBrowser wb = new WebBrowser())
            {
                wb.Width = w;
                wb.Height = h;
                wb.ScrollBarsEnabled = false;
                wb.Navigate(url);
                //确保页面被解析完全
                while (wb.ReadyState != WebBrowserReadyState.Complete)
                {
                    System.Windows.Forms.Application.DoEvents();
                }
                bitmap = new System.Drawing.Bitmap(w, h);
                wb.DrawToBitmap(bitmap, new System.Drawing.Rectangle(0, 0, w, h));
                wb.Dispose();
            }
        }
        private void CreatPdf(HttpContext context)
        {
            Document doc = new Document(PageSize.A4, 9, 18, 36, 36);//左右上下
            MemoryStream ms = new MemoryStream();
            try
            {
                PdfWriter writer = PdfWriter.GetInstance(doc, ms);
                writer.CloseStream = false;
                doc.Open();
                Thread thread = new Thread(new ThreadStart(setBitmap));
                thread.SetApartmentState(ApartmentState.STA);
                thread.Start();
                while (thread.IsAlive)
                    Thread.Sleep(100);
                byte[] i = img.OriginalData;
                img.ScalePercent(75);//560 630
                doc.Add(img);
                doc.NewPage();
                //doc.Add(img);
            }
            catch (Exception err)
            {
                throw new Exception(err.Message);
            }
            finally
            {
                doc.Close();
                ViewPdf(ms, context);
            }
        }        private void ViewPdf(Stream fs, HttpContext context)
        {
            context.Response.Clear();
            //中文名的话
            //context.Response.AppendHeader("Content-Disposition", "attachment;filename=" +
            //             HttpUtility.UrlEncode("中文.pdf"));
            string head = MakeUtil.getStringFromRequestByName(context.Request, "Head", -1);
            string filename = head +string.Format("{0:yyyyMMdd}",DateTime.Now.Date);
            context.Response.AddHeader("Content-Disposition", "inline;FileName=" + filename+".pdf");
            context.Response.ContentType = "application/pdf";
            
            long fileLength = fs.Length;
            int size = 10240;//10K一--分块下载，10K为1块
            byte[] readData = new byte[size];
            if (size > fileLength)
                size = Convert.ToInt32(fileLength);
            long fPos = 0;
            bool isEnd = false;
            while (!isEnd)
            {
                if ((fPos + size) >= fileLength)
                {
                    size = Convert.ToInt32(fileLength - fPos);
                    isEnd = true;
                }
                readData = new byte[size];
                fs.Position = fPos;
                fs.Read(readData, 0, size);
                context.Response.BinaryWrite(readData);
                context.Response.OutputStream.Flush();
                fPos += size;
            }
            fs.Close();
            context.Response.OutputStream.Close();
            context.Response.End();//非常重要，没有这句的话，页面的HTML代码将会保存到文件中
            context.Response.Close();
        }
部分代码如下，我想要的效果是分页，因为从html得到的图片高度大于A4的高度。我原来的思路是得到img对象后，读取高度的一部分，放到doc对象中，但是无法的到img的高度，比如0-100这部分图片。应该怎么做啊，哪个高手帮忙下，还是用别的方法！