public bool ExtractAllTextFromDwg(string inPdfFileName, string outTxtFileName, out string err) { bool result = false; string annotType = ""; string contents = ""; err = ""; try { if (isLibraryLoaded == false) { result = LoadPDFLib(); if (result == false) { return(result); } } int docId = pdfLib.LoadFromFile(inPdfFileName, ""); if (docId == 0) //failed { err += pdfLib.LastErrorCode(); return(false); } pdfLib.SelectDocument(docId); for (int pageNo = 1; pageNo <= pdfLib.PageCount(); ++pageNo) //Model contains no text { pdfLib.SelectPage(pageNo); for (int i = 1; i < pdfLib.AnnotationCount(); ++i) { annotType = pdfLib.GetAnnotStrProperty(i, 101); if (annotType.Equals("Square")) { contents += pdfLib.GetAnnotStrProperty(i, 102) + "\n"; //102 = contents } } } if (!string.IsNullOrWhiteSpace(contents)) { File.WriteAllText(outTxtFileName, contents); } } catch (Exception ex) { err += ex.Message + "\n"; err += pdfLib.LastErrorCode(); } return(result); }