iTextSharp AddText导致'An error exists on this page'

生成的PDF文档将显示“此页面上存在错误” . 在Acrobat Adobe Reader中打开时 . 有关为何发生这种情况的任何想法？它发生在旧版本的iTextSharp和我今天尝试的5.1.1版本中 .

测试代码：

static void PDFErrorOnPage()
  {
     Document document = new Document(PageSize.LETTER);
     float fMarginLeft = 15.822f; // 0.21975 inch
     float fMarginRight = 15.822f; // 0.21975 inch
     float fMarginTop = 36.0f;  // 0.5 inch
     float fMarginBottom = 36.0f;   // 0.5 inch
     float fLabelSpacingHorizontal = 10.08f;
     float fLabelWidth = 186.732f;
     float fLabelHeight = 72.0f;
     float fLabelPadding = 5.0f;
     float fLabelPaddingLeft = 20.0f;
     float fLabelPaddingBottom = 5.0f;
     float fLabelPaddingTop = 0.0f;
     int nRow = 0;
     int nCol = -1;
     bool bDebug = true;

     try
     {
        BaseFont bf = BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.WINANSI, BaseFont.NOT_EMBEDDED);
        Font font = new Font(bf, 8, Font.NORMAL, BaseColor.BLACK);
        Font fontBold = new Font(bf, 8, Font.BOLD, BaseColor.BLACK);

        PdfWriter writer = PdfWriter.GetInstance(document, new FileStream("d:\\tempjunk\\test.pdf", FileMode.Create));
        document.SetMargins(fMarginLeft, fMarginRight, fMarginTop, fMarginBottom);
        document.Open();

        PdfContentByte cb = writer.DirectContent;

        for (int i = 0; i < 26; i++)
        {
           nCol++;

           if (nCol > 2)
           {
              nCol = 0;
              nRow++;
           }
           if (nRow > 9)
           {
              nRow = 0;
              document.NewPage();
              Console.WriteLine("document.NewPage()");
           }

           float fLabelBottomLeftX = fMarginLeft + (nCol * fLabelSpacingHorizontal) + (nCol * fLabelWidth);
           float fLabelBottomLeftY = fMarginBottom + ((9 - nRow) * fLabelHeight);

           if (bDebug)
           {
              cb.SetRGBColorStroke(0x00, 0x00, 0xFF);
              cb.Rectangle(fLabelBottomLeftX, fLabelBottomLeftY, fLabelWidth, fLabelHeight);
              cb.Stroke();
           }

           cb.BeginText();

           ColumnText ct = new ColumnText(cb);
           ct.SetSimpleColumn(
              fLabelBottomLeftX + fLabelPaddingLeft,
              fLabelBottomLeftY + fLabelPaddingBottom,
              fLabelBottomLeftX + fLabelWidth - (fLabelPaddingLeft + fLabelPadding),
              fLabelBottomLeftY + fLabelHeight - (fLabelPaddingBottom + fLabelPaddingTop),
              12.0f,
              PdfContentByte.ALIGN_LEFT);
           ct.AddText(new Chunk("One\nTwo\nThree\nFour\nFive", font));
           ct.Go();

           cb.EndText();
        }
     }
     catch (Exception ex)
     {
        Console.WriteLine(ex.Message + " " + ex.StackTrace);
     }
     finally
     {
        if (document != null)
           document.Close();
     }
  }