CSS 样式未使用 iTextSharp 应用于 PDF

Question

我正在尝试使用 iTextSharp 将我的网页的一部分转换为 pdf，虽然 pdf 生成工作正常，但没有应用任何 css 样式。我试过一次应用一种样式，但这似乎不起作用。到目前为止，这是我想出的：

//Get the portion of the page to convert.
StringBuilder sb = new StringBuilder();
print_div.RenderControl(new HtmlTextWriter(new StringWriter(sb)));
string html = sb.ToString();

//Generate a random filename to use for the pdf
Guid random_guid;
random_guid = Guid.NewGuid();
string fileName = random_guid.ToString() + ".pdf";
string filename_with_folder = @"pdf\sl_" + fileName;
string fullFilePath = System.IO.Path.Combine(Request.PhysicalApplicationPath, filename_with_folder);

using (Document doc = new Document())
{
    // Create the pdf
    PdfWriter writer = PdfWriter.GetInstance(doc, new FileStream(fullFilePath, FileMode.Create));
    doc.Open();
    try
    {
        //Set the font size for all elements
        StyleSheet styles = new StyleSheet();
        styles.LoadStyle("body", "fontsize", "8px");

        //Write the content to the pdf document
        StringReader sr = new StringReader(html);
        XMLWorkerHelper.GetInstance().ParseXHtml(writer, doc, sr);
    }
    catch (Exception ex)
    {
    }
    doc.Close();
}

我错过了什么吗？我开始使用 HTMLWorker 并切换到 XMLWorker，但我想我现在只是让自己感到困惑。帮助将不胜感激。

尝试#2

感谢您的回复！这是我想出的，但它不起作用。我的内容现在根本没有出现在 pdf 中，我不知道为什么。有什么想法吗？

using (Document doc = new Document())
{
    PdfWriter writer = PdfWriter.GetInstance(doc, new FileStream(fullFilePath, FileMode.Create));
    doc.Open();

    // CSS
    var cssResolver = new StyleAttrCSSResolver();
    var cssFile = XMLWorkerHelper.GetCSS(new FileStream(HttpContext.Current.Server.MapPath("~/css/print.css"), FileMode.Open));
    cssResolver.AddCss(cssFile);

    // HTML
    CssAppliers ca = new CssAppliersImpl();
    HtmlPipelineContext hpc = new HtmlPipelineContext(ca);
    hpc.SetTagFactory(Tags.GetHtmlTagProcessorFactory());

    // PIPELINES
    PdfWriterPipeline pdf = new PdfWriterPipeline(doc, writer);
    HtmlPipeline htmlPipe = new HtmlPipeline(hpc, pdf);
    CssResolverPipeline css = new CssResolverPipeline(cssResolver, htmlPipe);

    XMLWorker worker = new XMLWorker(css, true);
    XMLParser p = new XMLParser(worker);
    StringReader sr = new StringReader(html);
    p.Parse(sr);
    doc.Close();
}

我是接近了，还是我完全没有抓住重点？

Answer 1

要使用样式表通过 XmlWorker 创建 PDF 文件，您可以尝试这个返回字节数组的示例代码。

        byte[] bytesArray = null;
        using (var ms = new MemoryStream())
        {
            using (var document = new Document())
            {
                using (PdfWriter writer = PdfWriter.GetInstance(document, ms))
                {
                    document.Open();
                    using (var strReader = new StringReader(html))
                    {
                        //Set factories
                        HtmlPipelineContext htmlContext = new HtmlPipelineContext(null);
                        htmlContext.SetTagFactory(Tags.GetHtmlTagProcessorFactory());
                        //Set css
                        ICSSResolver cssResolver = XMLWorkerHelper.GetInstance().GetDefaultCssResolver(false);
                        cssResolver.AddCssFile(System.Web.HttpContext.Current.Server.MapPath("~/Content/bootstrap.min.css"), true);
                        //Export
                        IPipeline pipeline = new CssResolverPipeline(cssResolver, new HtmlPipeline(htmlContext, new PdfWriterPipeline(document, writer)));
                        var worker = new XMLWorker(pipeline, true);
                        var xmlParse = new XMLParser(true, worker);
                        xmlParse.Parse(strReader);
                        xmlParse.Flush();
                    }
                    document.Close();
                }
            }
            bytesArray = ms.ToArray();
        }
        return bytesArray;

Answer 2

不确定您是否设法解决了这个问题，但我在 SO 上的问题“Cannot get CSS to work in iTextSharp (5.4.3) when making pdf”中没有应用 CSS 样式的问题。

基本上我发现样式表的某些部分正在应用（例如，表格单元格周围的边框），但其他部分没有应用（字体颜色，不在 PX 中的任何东西的大小）

Answer 3

您可以使用 CSSResolver 创建 XmlWorker

var cssResolver = new StyleAttrCSSResolver();
//Change the path to your CSS file
var cssFile = XMLWorkerHelper.GetCSS(new FileStream(HttpContext.Current.Server.MapPath("~/pdf.css"), FileMode.Open));
cssResolver.AddCss(cssFile);

然后创建您的 HtmlPipeline 并将其传递给 CssResolverPipeline 构造函数：

CssResolverPipeline css = new CssResolverPipeline(cssResolver, html);
XMLWorker worker = new XMLWorker(css, true);
XMLParser p = new XMLParser(worker); 
using (TextReader sr = new StringReader(html))
        {
            p.Parse(sr);
            document.Close();
        }
        //close your writer
        pdfwriter.Close();