我必须从PDF文件中检索文本。但是使用下面的代码我只得到空文本文件。
for (int i = 0; i < n; i++)
{
pagenumber = i + 1;
filename = pagenumber.ToString();
while (filename.Length < digits) filename = "0" + filename;
filename = "_" + filename;
filename = splitFile + name + filename;
// step 1: creation of a document-object
document = new Document(reader.GetPageSizeWithRotation(pagenumber));
// step 2: we create a writer that listens to the document
PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(filename + ".pdf", FileMode.Create));
// step 3: we open the document
document.Open();
PdfContentByte cb = writer.DirectContent;
PdfImportedPage page = writer.GetImportedPage(reader, pagenumber);
int rotation = reader.GetPageRotation(pagenumber);
if (rotation == 90 || rotation == 270)
{
cb.AddTemplate(page, 0, -1f, 1f, 0, 0, reader.GetPageSizeWithRotation(pagenumber).Height);
}
else
{
cb.AddTemplate(page, 1f, 0, 0, 1f, 0, 0);
}
// step 5: we close the document
document.Close();
PDFParser parser = new PDFParser();
parser.ExtractText(filename + ".pdf", filename + ".txt");
}
我做错了什么以及如何从PDF中提取文字?
答案 0 :(得分:9)
使用iTextSharp进行文本提取时,请获取该库的当前版本并使用
PdfTextExtractor.GetTextFromPage(reader, pageNumber);
请注意,某些5.3.x版本的文本提取代码中存在一个错误,同时已在主干中修复。因此,您可能想要检查主干版本。
答案 1 :(得分:4)
using System;
using System.IO;
using System.Linq;
using System.Text;
using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
namespace Pdf2Text
{
class Program
{
static void Main(string[] args)
{
if (!args.Any()) return;
var file = args[0];
var output = Path.ChangeExtension(file, ".txt");
if (!File.Exists(file)) return;
var bytes = File.ReadAllBytes(file);
File.WriteAllText(output, ConvertToText(bytes), Encoding.UTF8);
}
private static string ConvertToText(byte[] bytes)
{
var sb = new StringBuilder();
try
{
var reader = new PdfReader(bytes);
var numberOfPages = reader.NumberOfPages;
for (var currentPageIndex = 1; currentPageIndex <= numberOfPages; currentPageIndex++)
{
sb.Append(PdfTextExtractor.GetTextFromPage(reader, currentPageIndex));
}
}
catch (Exception exception)
{
Console.WriteLine(exception.Message);
}
return sb.ToString();
}
}
}
答案 2 :(得分:-2)
//call Create_pdf() function when Done button pressed;
EditText et_Text=findViewById(R.id.EditText);
String projectname="MyPdf";
public void Create_pdf(){
Document doc =new Document();
String outPath= Environment.getExternalStorageDirectory()+"/"+projectname+".pdf";
try {
PdfWriter.getInstance(doc, new FileOutputStream(outPath));
doc.open();
doc.add(new Paragraph(et_Text.getText().toString()));
doc.close();
} catch (DocumentException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}