从包含 html 代码的 MySql 表中创建 pdf 文件，使用 iText7 和 ASP NET ZD7EFA19FBE242236

Question

This is table t_contents_2021 on database MySql version 8.0.17

-- ----------------------------
-- Table structure for t_contents_2021
-- ----------------------------
DROP TABLE IF EXISTS `t_contents_2021`;
CREATE TABLE `t_contents_2021`  (
  `contents` varchar(1000)  DEFAULT NULL,
  `sUnity` varchar(255)  DEFAULT NULL,
  `sID_content_image` varchar(255)  DEFAULT NULL,
  `sID_content_image_link` varchar(255)  DEFAULT NULL,
  `sID_content_ppt` varchar(255)  DEFAULT NULL,
  `sID_content_ppt_link` varchar(255)  DEFAULT NULL,
  `sID_content_xls` varchar(255)  DEFAULT NULL,
  `sID_content_xls_link` varchar(255)  DEFAULT NULL,
  `sID_content_pdf` varchar(255)  DEFAULT NULL,
  `sID_content_pdf_link` varchar(255)  DEFAULT NULL,
  `sID` int(11) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`sID`) USING BTREE,
  UNIQUE INDEX `contents`(`contents`) USING BTREE
) ENGINE = InnoDB;

-- ----------------------------
-- Records of t_contents_2021
-- ----------------------------
INSERT INTO `t_contents_2021` VALUES ('Set 1', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 1);
INSERT INTO `t_contents_2021` VALUES ('- Par 1.1', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 2);
INSERT INTO `t_contents_2021` VALUES ('<b>bold text</b>', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 3);
INSERT INTO `t_contents_2021` VALUES ('- Par 1.2', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 4);
INSERT INTO `t_contents_2021` VALUES ('normal text', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 5);
INSERT INTO `t_contents_2021` VALUES ('Set 2', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 6);
INSERT INTO `t_contents_2021` VALUES ('- Par 2.1', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 7);
INSERT INTO `t_contents_2021` VALUES ('<i>italic text</i>', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 8);
INSERT INTO `t_contents_2021` VALUES ('- Par 2.2', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 9);
INSERT INTO `t_contents_2021` VALUES ('<u>underline text</u>', 'Q400', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 10);

On the table t_contents_2021 in field contents there is some html code

<b>bold text</b>
<i>italic text</i>
<u>underline text</u>

Now I use iText (Version 7.1.13) to convert html to pdf using HtmlConverter (html2pdf version 2.0.1)

string filename;
string html;
string dest;

Paragraph contents;

protected void Page_Load(object sender, EventArgs e)
{
    PdfWriter writer = new PdfWriter(Response.OutputStream);
    PdfDocument pdf = new PdfDocument(writer);
    Document document = new Document(pdf);

    using (MySqlConnection cn =
        new MySqlConnection(ConfigurationManager.ConnectionStrings["cn"].ConnectionString))
    {

        using (MySqlCommand cmd =
            new MySqlCommand("SP", cn))
        {
            cmd.Connection.Open();
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("tunity", "Q400");

            MySqlDataReader reader = cmd.ExecuteReader();

            if (reader.HasRows)
            {
                while (reader.Read())
                {
                    contents = new Paragraph(reader.GetString("contents"))
                    .SetTextAlignment(TextAlignment.JUSTIFIED)
                    .SetFontSize(12);

                    if (reader.GetString("contents").StartsWith("Set"))
                    {
                        contents.SetFontSize(12)
                            .SetBold()
                            .SetFontColor(ColorConstants.BLUE);
                        document.Add(newline);
                    }
                    else if (reader.GetString("contents").StartsWith("- "))
                    {
                        contents.SetFontSize(10)
                            .SetBold()
                            .SetFontColor(ColorConstants.BLACK);
                        document.Add(newline);
                    }
                    else
                    {
                        contents.SetFontSize(10)
                            .SetFontColor(ColorConstants.BLACK);
                    }

                    if (!String.IsNullOrEmpty(reader["sID_content_image"].ToString()))
                    {
                        Image image_path = new Image(ImageDataFactory
                              .Create(reader["sID_content_image"].ToString()))
                              .SetTextAlignment(TextAlignment.CENTER);

                        image_path.SetAutoScale(false);
                        image_path.SetBorderLeft(new SolidBorder(ColorConstants.DARK_GRAY, 2));
                        image_path.SetBorderRight(new SolidBorder(ColorConstants.DARK_GRAY, 2));
                        image_path.SetBorderTop(new SolidBorder(ColorConstants.DARK_GRAY, 2));
                        image_path.SetBorderBottom(new SolidBorder(ColorConstants.DARK_GRAY, 2));
                        document.Add(image_path);
                    }

                    if (!String.IsNullOrEmpty(reader["sID_content_ppt"].ToString()))
                    {
                        string IMG1 = "C:\\inetpub\\wwwroot\\aspnet\\img\\powerpoint-png-picture-2.jpg";
                        Image img1 = new Image(ImageDataFactory.Create(IMG1));
                        Table tablelink = new Table(UnitValue.CreatePercentArray(1)).UseAllAvailableWidth();
                        PdfFont font = PdfFontFactory.CreateFont(StandardFonts.HELVETICA_BOLD);

                        Cell cell = new Cell().Add(img1.SetAutoScale(false));
                        cell.SetHorizontalAlignment(HorizontalAlignment.CENTER);
                        img1.SetHorizontalAlignment(HorizontalAlignment.CENTER);
                        cell.SetBorder(Border.NO_BORDER);

                        cell.SetAction(PdfAction.CreateURI(
                            reader["sID_content_ppt_link"].ToString()));
                        tablelink.AddCell(cell);
                        document.Add(tablelink);
                        document.Add(newline);
                    }

                    if (!String.IsNullOrEmpty(reader["sID_content_xls"].ToString()))
                    {
                        string IMG1 = "C:\\inetpub\\wwwroot\\img\\excel-2.png";
                        Image img1 = new Image(ImageDataFactory.Create(IMG1));
                        Table tablelink = new Table(UnitValue.CreatePercentArray(1)).UseAllAvailableWidth();
                        PdfFont font = PdfFontFactory.CreateFont(StandardFonts.HELVETICA_BOLD);
                        Cell cell = new Cell().Add(img1.SetAutoScale(false));
                        cell.SetHorizontalAlignment(HorizontalAlignment.CENTER);
                        img1.SetHorizontalAlignment(HorizontalAlignment.CENTER);
                        cell.SetBorder(Border.NO_BORDER);
                        cell.SetAction(PdfAction.CreateURI(
                            reader["sID_content_xls_link"].ToString()));
                        tablelink.AddCell(cell);
                        document.Add(tablelink);
                        document.Add(newline);
                    }

                    if (!String.IsNullOrEmpty(reader["sID_content_pdf"].ToString()))
                    {
                        string IMG1 = "C:\\inetpub\\wwwroot\\img\\pdf-png-picture-2.gif";
                        Image img1 = new Image(ImageDataFactory.Create(IMG1));
                        Table tablelink = new Table(UnitValue.CreatePercentArray(1)).UseAllAvailableWidth();
                        PdfFont font = PdfFontFactory.CreateFont(StandardFonts.HELVETICA_BOLD);
                        Cell cell = new Cell().Add(img1.SetAutoScale(false));
                        cell.SetHorizontalAlignment(HorizontalAlignment.CENTER);
                        img1.SetHorizontalAlignment(HorizontalAlignment.CENTER);
                        cell.SetBorder(Border.NO_BORDER);
                        cell.SetAction(PdfAction.CreateURI(
                            reader["sID_content_pdf_link"].ToString()));
                        tablelink.AddCell(cell);
                        document.Add(tablelink);
                        document.Add(newline);
                    }

                    document.Add(contents);
                }

                filename = @"C:\\inetpub\\wwwroot\\public\\Management_" + Guid.NewGuid() + ".pdf";
                html = contents.ToString();
                dest = filename.ToString();
                HtmlConverter.ConvertToPdf(html, new FileStream(dest, FileMode.Create));
            }
            else
            {
                Console.WriteLine("No rows found.");
            }

            reader.Close();
            cmd.Connection.Close();
        }
    }

    document.Close();

    Response.Clear();
    Response.ContentType = "application/pdf";
    Response.AppendHeader("Content-Disposition", "attachment; filename=" + dest);
    Response.TransmitFile(dest);
    Response.End();
}

The generated pdf file Management_14a40257-547f-4b6f-b991-eaa4aeb47a9a.pdf doesn't contains the values from table t_contents_2021 but contains only this text:

If not use on my code the HtmlConverter.ConvertToPdf

filename = @"C:\\inetpub\\wwwroot\\public\\Management_" + Guid.NewGuid() + ".pdf";
html = contents.ToString();
dest = filename.ToString();
HtmlConverter.ConvertToPdf(html, new FileStream(dest, FileMode.Create));
        

the pdf file is created correctly but on pdf I have

Help me to do it

This is the Stored procedure in MySql

CREATE DEFINER=`root`@`localhost` PROCEDURE `SP`(IN tunity CHAR(100))
BEGIN

SET @s = CONCAT('SELECT * FROM t_contents_2021 WHERE sUnity = \'',tunity,'\';');
PREPARE stmt FROM @s;
EXECUTE stmt;
DEALLOCATE PREPARE `stmt`;

END

Answer 1

This line of code is wrong:

html = contents.ToString();

contents is a iText.Layout.Element.Paragraph object; calling .ToString() on it returns the name of the type. Converting that string to PDF produces the output you see.

You need to find another API to save document to a PDF.