如何在c#中逐行读取PDF文件？

Question

In my windows 8 application, I would like to read a PDF line by line then I would like to assign a String array. How can I do it?

    public StringBuilder addd= new StringBuilder();
    string[] array;

    private async void btndosyasec_Click(object sender, RoutedEventArgs e)
    {
        FileOpenPicker openPicker = new FileOpenPicker();
        openPicker.ViewMode = PickerViewMode.List;
        openPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
        openPicker.FileTypeFilter.Add(".pdf");

        StorageFile file = await openPicker.PickSingleFileAsync();



        if (file != null)
        {

            PdfReader reader = new PdfReader((await file.OpenReadAsync()).AsStream());

            for (int page = 1; page <= reader.NumberOfPages; page++)
            {

                addd.Append(PdfTextExtractor.GetTextFromPage(reader, page));
                string tmp= PdfTextExtractor.GetTextFromPage(reader, page);

                array[page] = tmp.ToString();

                reader.Close();
            }
        }
    }

Answer 1

Hi I had this problem too, I used this code, it worked.

You will need a reference to the iTextSharp lib.

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

PdfReader reader = new PdfReader(@"D:\test pdf\Blood Journal.pdf");
int intPageNum = reader.NumberOfPages;
string[] words;
string line;

    for (int i = 1; i <= intPageNum; i++)
    {
        text = PdfTextExtractor.GetTextFromPage(reader, i, new LocationTextExtractionStrategy());

        words = text.Split('\n');
        for (int j = 0, len = words.Length; j < len; j++)
        {
            line = Encoding.UTF8.GetString(Encoding.UTF8.GetBytes(words[j]));
        }
    }

words array contains lines of pdf file

Answer 2

Below code work for iText7

using iText.Kernel.Pdf;
using iText.Kernel.Pdf.Canvas.Parser;
using iText.Kernel.Pdf.Canvas.Parser.Listener;


public void ExtractTextFromPDF(string filePath)
{
    PdfReader pdfReader = new PdfReader(filePath);
    PdfDocument pdfDoc = new PdfDocument(pdfReader);

    for (int page = 1; page <= pdfDoc.GetNumberOfPages(); page++)
    {
        ITextExtractionStrategy strategy = new SimpleTextExtractionStrategy();
        string pageContent = PdfTextExtractor.GetTextFromPage(pdfDoc.GetPage(page), strategy);

        Console.WriteLine("pageContent : " + pageContent);
    }
    pdfDoc.Close();
    pdfReader.Close();
}

Answer 3

If you are looking for something Licence Free/Open Source with basic text extraction from PDF, then you can go for PdfClown which has Support for both .Net Framework as well as .NET CORE (though Beta version wrt .NET Standard 2.0). For More Info or Samples, take look at

https://www.nuget.org/packages/PdfClown.NetStandard/0.2.0-beta

https://sourceforge.net/p/clown/code/HEAD/tree/trunk/dotNET/pdfclown.samples.cli/

Below sample is wrt .NET CORE.

public class PdfClownUtil
{
    private static readonly string fileSrcPath = "MyTestDoc.pdf";
    private readonly StringBuilder stringBuilder_1 = new StringBuilder();
    public string GetPdfTextContent()
    {
        PdfDocuments.Document document = new File(fileSrcPath).Document;
        StringBuilder stringBuilder_2 = new StringBuilder();

        TextExtractor extractor = new TextExtractor();
        foreach (Page page in document.Pages)
        {
            // Approach-1: 
            Extract(new ContentScanner(page));

            // Approach-2 with additional Options: 
            IList<ITextString> textStrings = extractor.Extract(page)[TextExtractor.DefaultArea];
            foreach (ITextString textString in textStrings)
            {
                stringBuilder_2.Append(textString.Text);
            }
            stringBuilder_2.AppendLine();
        }
        var content = stringBuilder_2.ToString();
        return content;
    }

    // Approach-1: 
    private void Extract(ContentScanner level)
    {
        if (level == null)
        {
            return;
        }                

        while (level.MoveNext())
        {
            ContentObject content = level.Current;
            if (content is ShowText)
            {
                Font font = level.State.Font;
                // Extract the current text chunk, decoding it!
                this.stringBuilder_1.Append(font.Decode(((ShowText)content).Text));
            }
            else if (content is Text || content is ContainerObject)
            {
                // Scan the inner level!
                Extract(level.ChildLevel);
            }
        }
    }
}