如何为 iText7 使用 html 字符串

Question

我正在尝试通过 itext7 使用 asp.net webforms 显示（只是显示而不是下载）基于 html 字符串（不确定这是否是正确的术语？）的 pdf。

using iText.Kernel.Geom;
using iText.Kernel.Pdf;
using iText.Layout;
using iText.Layout.Element;
using iText.Layout.Font;
using iText.Layout.Properties;
//I think I'm missing something here? I added itext7pdfhtml via nuget but not sure how to reference it.

using (var memoryStream = new MemoryStream())
{
   var pdfWriter = new PdfWriter(memoryStream);
   var pdfDocument = new PdfDocument(pdfWriter);
   var document = new Document(pdfDocument, PageSize.LETTER, true);
 //pdfDocument.getCatalog().setOpenAction;
   FontProvider provider = new FontProvider();
   provider.AddFont("Arial");

   StringBuilder sb = new StringBuilder();

     sb.Append("<table width='100%' cellspacing='0' cellpadding='2' style='border: 20px solid #ccc;font-size: 9pt;font-family:Arial'>");
     sb.Append("<tr><td align='center' style='background-color: blue' ><b>Sample</b></td></tr>");
     sb.Append("<tr><td colspan = '2'></td></tr>");
     sb.Append("<tr><td>");
     sb.Append("<b>Sample:</b>");
     sb.Append("</td><td align = 'right'><b>Sample</b>");
  // sb.Append(DateTime.Now);
     sb.Append(" </td></tr>");
     sb.Append("<tr><td colspan = '2'><b>This is example: </b>");
     sb.Append("this is trial");
     sb.Append("</td></tr>");
     sb.Append("</table>");
     sb.Append("<br />");

  // document = HtmlConverter.convertToPdf(sb.ToString(), memoryStream); // htmlconverter not found, already added itext7htmlpdf via nuget, not sure how to reference?
     document.Close();
     bytes = memoryStream.ToArray();
    }
string base64PDF = System.Convert.ToBase64String(bytes, 0, bytes.Length);
            string str = "<embed src='data:application/pdf;base64, " + base64PDF + "' type='application/pdf' width='500px' height='800px' />";
            pdfdiv.InnerHtml = str; // basically showing the pdf here. this already works if I use  document.Add(new Paragraph("test"));

我的问题是htmlconverter的正确引用和正确实现？

编辑：这些是当前通过 nuget 安装的以下内容：

试过：使用 iText.Html2pdf 但不存在报错。

Answer 1

您确实缺少用于 iText.Html2pdf 命名空间的 using 指令，其中包含 HtmlConverter。

除了using 指令，您还可以尝试使用完全限定名称来验证您的项目中是否正确安装了pdfHTML：iText.Html2pdf.HtmlConverter.ConvertToPdf(...)

这是一个完整的示例，展示了如何使用HtmlConverter：

using System.IO;
using System.Text;
using iText.Html2pdf;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            byte[] bytes;

            using (var memoryStream = new MemoryStream())
            {
                StringBuilder sb = new StringBuilder();

                sb.Append("<table width='100%' cellspacing='0' cellpadding='2' style='border: 20px solid #ccc;font-size: 9pt;font-family:Arial'>");
                sb.Append("<tr><td align='center' style='background-color: blue' ><b>Sample</b></td></tr>");
                sb.Append("<tr><td colspan = '2'></td></tr>");
                sb.Append("<tr><td>");
                sb.Append("<b>Sample:</b>");
                sb.Append("</td><td align = 'right'><b>Sample</b>");
                // sb.Append(DateTime.Now);
                sb.Append(" </td></tr>");
                sb.Append("<tr><td colspan = '2'><b>This is example: </b>");
                sb.Append("this is trial");
                sb.Append("</td></tr>");
                sb.Append("</table>");
                sb.Append("<br />");

                HtmlConverter.ConvertToPdf(sb.ToString(), memoryStream);
                //iText.Html2pdf.HtmlConverter.ConvertToPdf(sb.ToString(), memoryStream);

                bytes = memoryStream.ToArray();
            }
            // writing PDF output to file for testing
            File.WriteAllBytes("test.pdf", bytes);
            //string base64PDF = System.Convert.ToBase64String(bytes, 0, bytes.Length);
            //string str = "<embed src='data:application/pdf;base64, " + base64PDF + "' type='application/pdf' width='500px' height='800px' />";
            //pdfdiv.InnerHtml = str;
        }
    }
}