public class PDFSetWaterMark{    /// <summary>    /// 創建一個顯示指定圖片的pdf    /// </summary>    /// <param name="picPdfPath"></param>    /// <param name="picPath"></param>    /// <returns></returns>    public static bool CreatePDFByPic(string picPdfPath, string picPath)    {      //新建一個文檔      Document doc = new Document();      try      {        //建立一個書寫器(Writer)與document對象關聯        PdfWriter.GetInstance(doc, new FileStream(picPdfPath, FileMode.Create, FileAccess.ReadWrite));        //打開一個文檔        doc.Open();        //向文檔中添加內容        Image img = Image.GetInstance(picPath);        //img.SetAbsolutePosition();        doc.Add(img);        return true;      }      catch (Exception ex)      {        return false;        throw ex;      }      finally      {        if (doc != null)        {          doc.Close();        }      }    }    /// <summary>    /// 加圖片水印    /// </summary>    /// <param name="inputfilepath"></param>    /// <param name="outputfilepath"></param>    /// <param name="ModelPicName"></param>    /// <param name="top"></param>    /// <param name="left"></param>    /// <returns></returns>    public static bool PDFWatermark(string inputfilepath, string outputfilepath, string ModelPicName, float top, float left)    {      //throw new NotImplementedException();      PdfReader pdfReader = null;      PdfStamper pdfStamper = null;      try      {        pdfReader = new PdfReader(inputfilepath);        int numberOfPages = pdfReader.NumberOfPages;        iTextSharp.text.Rectangle psize = pdfReader.GetPageSize(1);        float width = psize.Width;        float height = psize.Height;        pdfStamper = new PdfStamper(pdfReader, new FileStream(outputfilepath, FileMode.Create));        PdfContentByte waterMarkContent;        iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(ModelPicName);        image.GrayFill = 20;//透明度，灰色填充        //image.Rotation//旋轉        //image.RotationDegrees//旋轉角度        //水印的位置        if (left < 0)        {          left = width / 2 - image.Width + left;        }        //image.SetAbsolutePosition(left, (height - image.Height) - top);        image.SetAbsolutePosition(left, (height / 2 - image.Height) - top);        //每一頁加水印,也可以設置某一頁加水印        for (int i = 1; i <= numberOfPages; i++)        {          //waterMarkContent = pdfStamper.GetUnderContent(i);//內容下層加水印          waterMarkContent = pdfStamper.GetOverContent(i);//內容上層加水印          waterMarkContent.AddImage(image);        }        //strMsg = "success";        return true;      }      catch (Exception ex)      {        throw ex;      }      finally      {        if (pdfStamper != null)          pdfStamper.Close();        if (pdfReader != null)          pdfReader.Close();      }    }    /// <summary>    /// 添加普通偏轉角度文字水印    /// </summary>    /// <param name="inputfilepath"></param>    /// <param name="outputfilepath"></param>    /// <param name="waterMarkName"></param>    /// <param name="permission"></param>    public static void setWatermark(string inputfilepath, string outputfilepath, string waterMarkName)    {      PdfReader pdfReader = null;      PdfStamper pdfStamper = null;      try      {        pdfReader = new PdfReader(inputfilepath);        pdfStamper = new PdfStamper(pdfReader, new FileStream(outputfilepath, FileMode.Create));        int total = pdfReader.NumberOfPages + 1;        iTextSharp.text.Rectangle psize = pdfReader.GetPageSize(1);        float width = psize.Width;        float height = psize.Height;        PdfContentByte content;        BaseFont font = BaseFont.CreateFont(@"C:/WINDOWS/Fonts/SIMFANG.TTF", BaseFont.IDENTITY_H, BaseFont.EMBEDDED);        PdfGState gs = new PdfGState();        for (int i = 1; i < total; i++)        {          content = pdfStamper.GetOverContent(i);//在內容上方加水印          //content = pdfStamper.GetUnderContent(i);//在內容下方加水印          //透明度          gs.FillOpacity = 0.3f;          content.SetGState(gs);          //content.SetGrayFill(0.3f);          //開始寫入文本          content.BeginText();          content.SetColorFill(BaseColor.LIGHT_GRAY);          content.SetFontAndSize(font, 100);          content.SetTextMatrix(0, 0);          content.ShowTextAligned(Element.ALIGN_CENTER, waterMarkName, width / 2 - 50, height / 2 - 50, 55);          //content.SetColorFill(BaseColor.BLACK);          //content.SetFontAndSize(font, 8);          //content.ShowTextAligned(Element.ALIGN_CENTER, waterMarkName, 0, 0, 0);          content.EndText();        }      }      catch (Exception ex)      {        throw ex;      }      finally      {        if (pdfStamper != null)          pdfStamper.Close();        if (pdfReader != null)          pdfReader.Close();      }    }    /// <summary>    /// 添加傾斜水印    /// </summary>    /// <param name="inputfilepath"></param>    /// <param name="outputfilepath"></param>    /// <param name="waterMarkName"></param>    /// <param name="userPassWord"></param>    /// <param name="ownerPassWord"></param>    /// <param name="permission"></param>    public static void setWatermark(string inputfilepath, string outputfilepath, string waterMarkName, string userPassWord, string ownerPassWord, int permission)    {      PdfReader pdfReader = null;      PdfStamper pdfStamper = null;      try      {        pdfReader = new PdfReader(inputfilepath);        pdfStamper = new PdfStamper(pdfReader, new FileStream(outputfilepath, FileMode.Create));        // 設置密碼        //pdfStamper.SetEncryption(false,userPassWord, ownerPassWord, permission);        int total = pdfReader.NumberOfPages + 1;        PdfContentByte content;        BaseFont font = BaseFont.CreateFont(@"C:/WINDOWS/Fonts/SIMFANG.TTF", BaseFont.IDENTITY_H, BaseFont.EMBEDDED);        PdfGState gs = new PdfGState();        gs.FillOpacity = 0.2f;//透明度        int j = waterMarkName.Length;        char c;        int rise = 0;        for (int i = 1; i < total; i++)        {          rise = 500;          content = pdfStamper.GetOverContent(i);//在內容上方加水印          //content = pdfStamper.GetUnderContent(i);//在內容下方加水印          content.BeginText();          content.SetColorFill(BaseColor.DARK_GRAY);          content.SetFontAndSize(font, 50);          // 設置水印文字字體傾斜 開始          if (j >= 15)          {            content.SetTextMatrix(200, 120);            for (int k = 0; k < j; k++)            {              content.SetTextRise(rise);              c = waterMarkName[k];              content.ShowText(c + "");              rise -= 20;            }          }          else          {            content.SetTextMatrix(180, 100);            for (int k = 0; k < j; k++)            {              content.SetTextRise(rise);              c = waterMarkName[k];              content.ShowText(c + "");              rise -= 18;            }          }          // 字體設置結束          content.EndText();          // 畫一個圓          //content.Ellipse(250, 450, 350, 550);          //content.SetLineWidth(1f);          //content.Stroke();        }      }      catch (Exception ex)      {        throw ex;      }      finally      {        if (pdfStamper != null)          pdfStamper.Close();        if (pdfReader != null)          pdfReader.Close();      }    }}