ITextSharpを使用してpdfのテキスト内容を読み込む

using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;


//          pdf  ，           PdfReader

PdfReader reader = new PdfReader(ofd.FileName);

PdfReaderContentParser parser = new PdfReaderContentParser(reader);

ITextExtractionStrategy strategy;
strategy= parser.ProcessContent<SimpleTextExtractionStrategy>(1,new SimpleTextExtractionStrategy());
//              
rtbContent.Text = strategy.GetResultantText();