您还可以实现将 pdf 的内容放入 XmlDocument 并像使用 XML 一样工作。这是我用来替换在文本框中编写的一些占位符的代码。
PdfReader pdfReader = new PdfReader(path_pdf);
using (PdfStamper pdfStamp = new PdfStamper(pdfReader, new FileStream(temp_path, FileMode.Create), '\0', true))
{
pdfStamp.ViewerPreferences = PdfWriter.AllowModifyContents;
XmlDocument xmlDocument = pdfReader.AcroFields.Xfa.DomDocument;
string pdfContent = xmlDocument.InnerXml;
string newpdfContent = pdfContent
.Replace("$CONTENT_TO_REPLACE_1$", "some_content")
.Replace("$CONTENT_TO_REPLACE_2$", "some_other_content")
xmlDocument.InnerXml = newpdfContent;
Stream stream = GenerateStreamFromString(newpdfContent);
pdfStamp.AcroFields.Xfa.FillXfaForm(stream);
pdfStamp.AcroFields.Xfa.DomDocument = xmlDocument;
pdfStamp.Close();
}