c# - 使用 iText7 C# 解析/读取 PDF 文档

Question

我正在尝试使用 iText7 库来升级我的代码。以前我使用 iTextSharp 库但看起来 iText7 是全新的我尝试阅读 pdf 文档但在“找不到 Pdf Header”之间遇到异常。这是我的代码

byte[] bytes = System.Convert.FromBase64String(UploadedFileByes);

MemoryStream memory = new MemoryStream(bytes);
            BinaryReader BRreader = new BinaryReader(memory);
            StringBuilder text = new StringBuilder();


            iText.Kernel.Pdf.PdfReader iTextReader = new iText.Kernel.Pdf.PdfReader(memory);
            iText.Kernel.Pdf.PdfDocument pdfDoc = new iText.Kernel.Pdf.PdfDocument(new iText.Kernel.Pdf.PdfReader(memory));



            int numberofpages = pdfDoc.GetNumberOfPages();
            for (int page = 1; page <= numberofpages; page++) {
                iText.Kernel.Pdf.Canvas.Parser.Listener.ITextExtractionStrategy strategy = new iText.Kernel.Pdf.Canvas.Parser.Listener.SimpleTextExtractionStrategy();
                string currentText = iText.Kernel.Pdf.Canvas.Parser.PdfTextExtractor.GetTextFromPage(pdfDoc.GetPage(page),strategy);
                currentText = Encoding.UTF8.GetString(ASCIIEncoding.Convert(
                    Encoding.Default, Encoding.UTF8, Encoding.Default.GetBytes(currentText)));
                text.Append(currentText);
            }

我究竟做错了什么？

标签： c#itextitext7pdf-reader

Answer 1

我得到了解决方案。我使用了我定义的 pdfreader，而不是创建新的。这是代码。希望它会帮助某人。

byte[] bytes = System.Convert.FromBase64String(UploadedFileByes);

MemoryStream memory = new MemoryStream(bytes);
            BinaryReader BRreader = new BinaryReader(memory);
            StringBuilder text = new StringBuilder();


            iText.Kernel.Pdf.PdfReader iTextReader = new iText.Kernel.Pdf.PdfReader(memory);
            iText.Kernel.Pdf.PdfDocument pdfDoc = new iText.Kernel.Pdf.PdfDocument(iTextReader);



            int numberofpages = pdfDoc.GetNumberOfPages();
            for (int page = 1; page <= numberofpages; page++) {
                iText.Kernel.Pdf.Canvas.Parser.Listener.ITextExtractionStrategy strategy = new iText.Kernel.Pdf.Canvas.Parser.Listener.SimpleTextExtractionStrategy();
                string currentText = iText.Kernel.Pdf.Canvas.Parser.PdfTextExtractor.GetTextFromPage(pdfDoc.GetPage(page),strategy);
                currentText = Encoding.UTF8.GetString(ASCIIEncoding.Convert(
                    Encoding.Default, Encoding.UTF8, Encoding.Default.GetBytes(currentText)));
                text.Append(currentText);
            }