public void Encryption(PdfDocument pdfDocument)
        {
            Configuration c = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            if (!string.IsNullOrEmpty(c.AppSettings.Settings["UserPassword"].Value))
            {
                pdfDocument.Security.UserPassword = c.AppSettings.Settings["UserPassword"].Value;
            }
            if (!string.IsNullOrEmpty(c.AppSettings.Settings["OwnPassword"].Value))
            {
                pdfDocument.Security.OwnerPassword = c.AppSettings.Settings["OwnPassword"].Value;
            }
            int Permissions;
            if (!string.IsNullOrEmpty(c.AppSettings.Settings["Permissions"].Value))
            {
                int.TryParse(c.AppSettings.Settings["Permissions"].Value, out Permissions);
                pdfDocument.Security.Permissions = (pdfSecurity.PdfPermissionsFlags)Permissions;
            }
        }

public void WaterMark(PdfPageCollection pages)
        {
            Configuration c = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            if (!string.IsNullOrEmpty(c.AppSettings.Settings["TextWatermark"].Value))
            {
                foreach (PdfPageBase page in pages)
                {
                    TextWaterMark(page);
                }
            }
            if (!string.IsNullOrEmpty(c.AppSettings.Settings["ImageWatermark"].Value))
            {
                foreach (PdfPageBase page in pages)
                {
                    ImageWaterMark(page);
                }
            }
        }

          

          public static IConvertable GetConverter(string fileFullName)
        {
            FileInfo fi = new FileInfo(fileFullName);
            if (!File.Exists(fileFullName))
            {
                throw new Exception(fi.Name + " is not existed!");
            }
            switch (Path.GetExtension(fileFullName).ToLower())
            {
                case ".doc":
                case ".docx":
                case ".rtf":
                    return new WordConverter();
                case ".htm":
                case ".html":
                    return new HTMLConverter();
                case ".xls":
                case ".xlsx":
                    return new ExcelConverter();
                case ".txt":
                    return new TextConverter();
                case ".jpg":
                case ".png":
                case ".bmp":
                case ".gif":
                case ".tiff":
                    return new ImageConverter();
                default:
                    throw new Exception(fi.Name + " can not convert to pdf!");
            }
        }

          

          public class ExcelConverter : BaseConverter, IConvertable
    {
        #region IConvertable 

        public void Convert(string fileFullName)
        {
            if (!File.Exists(fileFullName))
            {
                throw new Exception(string.Format("{0} does not exist!", fileFullName));
            }
            Spire.Xls.Converter.PdfConverter pdfConverter = new Spire.Xls.Converter.PdfConverter(fileFullName);

            PdfDocument pdfDocument = new PdfDocument();
           
            pdfDocument.PageSettings.Orientation = pdf.PdfPageOrientation.Landscape;
            pdfDocument.PageSettings.Width = 970;
            pdfDocument.PageSettings.Height = 850;

            PdfConverterSettings settings = new PdfConverterSettings();
            settings.EmbedFonts = true;
            settings.TemplateDocument = pdfDocument;
            pdfDocument = pdfConverter.Convert(settings);
            //WaterMark(pdfDocument);
#if !FreeEdition
            WaterMark(pdfDocument.Pages);
            Encryption(pdfDocument);
#endif
            Configuration c = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            string savePath = Path.Combine(c.AppSettings.Settings["OutputFile"].Value, Path.GetFileName(fileFullName) + ".pdf");
            pdfDocument.SaveToFile(savePath);
            pdfDocument.Close();
        }

        #endregion
}


public class WordConverter : BaseConverter, IConvertable
    {
        #region IConvertable 

        public void Convert(string fileFullName)
        {
            if (!File.Exists(fileFullName))
            {
                throw new Exception(string.Format("{0} does not exist!", fileFullName));
            }
            Document document = new Document();
            document.LoadFromFile(fileFullName);
            Configuration c = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            string savePath = Path.Combine(c.AppSettings.Settings["OutputFile"].Value, Path.GetFileName(fileFullName) + ".pdf");
            using (MemoryStream stream = new MemoryStream())
            {
                document.SaveToStream(stream, FileFormat.PDF);
                document.Close();
                PdfDocument pdfdoc = new PdfDocument(stream);
                //WaterMark(pdfdoc);
#if !FreeEdition
                WaterMark(pdfdoc.Pages);
                Encryption(pdfdoc);
#endif

                pdfdoc.SaveToFile(savePath);
                pdfdoc.Close();
            }
        }

        #endregion
    }


public class HTMLConverter : BaseConverter, IConvertable
    {
        #region IConvertable 

        public void Convert(string fileFullName)
        {
            if (!File.Exists(fileFullName))
            {
                throw new Exception(string.Format("{0} does not exist!", fileFullName));
            }
            PdfDocument pdfdoc = new PdfDocument();
            //pdfdoc.Sections.Add().LoadFromHTML(fileFullName, true, true, new Spire.Pdf.HtmlConverter.PdfHtmlLayoutFormat() { FitToPage = Spire.Pdf.HtmlConverter.Clip.Width, Layout = pdfGraphics.PdfLayoutType.Paginate });
            pdfdoc.LoadFromHTML(fileFullName, true, true, true);
            //pdfdoc.LoadFromFile(url);
            FileInfo fi = new FileInfo(fileFullName);
            Configuration c = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            string savePath = Path.Combine(c.AppSettings.Settings["OutputFile"].Value, Path.GetFileName(fileFullName) + ".pdf");
            //WaterMark(pdfdoc);
#if !FreeEdition
            WaterMark(pdfdoc.Pages);
            Encryption(pdfdoc);
#endif
            pdfdoc.SaveToFile(savePath);
            pdfdoc.Close();
        }

        #endregion
    }


public class ImageConverter : BaseConverter, IConvertable
    {
      #region IConvertable 

        public void Convert(string fileFullName)
        {
            if (!File.Exists(fileFullName))
            {
                throw new Exception(string.Format("{0} does not exist!", fileFullName));
            }
            PdfDocument doc = new PdfDocument();
            PdfSection section = doc.Sections.Add();
           
            PdfPageBase page = doc.Pages.Add();
            PdfImage image = PdfImage.FromFile(fileFullName);

            float widthFitRate = image.PhysicalDimension.Width / page.Canvas.ClientSize.Width;
            float heightFitRate = image.PhysicalDimension.Height / page.Canvas.ClientSize.Height;
            float fitRate = Math.Max(widthFitRate, heightFitRate);
            float fitWidth = image.PhysicalDimension.Width / fitRate;
            float fitHeight = image.PhysicalDimension.Height / fitRate;

            page.Canvas.DrawImage(image, 0, 0, fitWidth, fitHeight);
            Configuration c = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            string savePath = Path.Combine(c.AppSettings.Settings["OutputFile"].Value, Path.GetFileName(fileFullName) + ".pdf");
            //WaterMark(doc);
#if !FreeEdition
            WaterMark(doc.Pages);
            Encryption(doc);
#endif
            doc.SaveToFile(savePath);
            doc.Close();
        } 
        #endregion
    }