在ITextSharp PDF上渲染CSS

Question

我正在使用以下代码在.NET Core API中生成并保存PDF文档。它可以工作并生成PDF，但是PDF缺少了HTML本身包含的所有样式。如何链接CSS文件或启用HTML中的CSS渲染？

[HttpGet]
public ActionResult GeneratePDF()
{
    string contentRootPath = _hostingEnvironment.ContentRootPath;
    var folderName = Path.Combine(contentRootPath, FileHandler.InvoicesAttachmentsPath);

    if (!Directory.Exists(folderName))
        Directory.CreateDirectory(folderName);

    string html = PDF.GetPdfHTMLString();

    StringReader sr = new StringReader(html.ToString());

    Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);

    HTMLWorker htmlparser = new HTMLWorker(pdfDoc);


    using (MemoryStream memoryStream = new MemoryStream())
    {
        //PdfWriter writer = PdfWriter.GetInstance(pdfDoc, memoryStream, FileMode.Create);
        PdfWriter.GetInstance(pdfDoc, new FileStream(Path.Combine(folderName, "mypdf.pdf"), FileMode.Create));
        pdfDoc.Open();

        htmlparser.Parse(sr);
        pdfDoc.Close();

        byte[] bytes = memoryStream.ToArray();
        memoryStream.Close();
    }

    return Ok("");


}