通过C＃复制PDF注释 [英] Copy pdf annotations via C#

问题描述

我有一个数据流（PDF文件注解）和另一个流（不标注相同的PDF文件）。我使用流，因为我需要在内存中执行此操作。 我需要说明复制从第一个到另一个文件。注释可以是不同的：注释，高亮等。因此，最好是复制的注解，而不分析它。

I have a stream (PDF file with annotations) and another stream (the same PDF file without annotations). I use streams because I need to execute this operations in memory. I need to copy annotations from first document to another. Annotations can be different: comments, highlighting and other. So it is better to copy annotations without parsing it.

你能指点我要.NET一些有用的PDF库？而一些样品这个问题。

Can you advice me some helpful PDF library for .NET? And some sample for this problem.

推荐答案

我使用iTextSharp的是从iText的分叉（一个java实行FPR的PDF编辑）。

I'm using ITextSharp which is forked from IText (a java implemenation fpr pdf editing).

http://sourceforge.net/projects/itextsharp/

http://itextpdf.com/

编辑 - 这就是你需要做的（未经测试，但建议立即进行删除接近）：

Edit - this is what you need to do (untested but shoul be close):

using System;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

// return processed stream (a new MemoryStream) 
public Stream copyAnnotations(Stream sourcePdfStream, Stream destinationPdfStream)
{
    // Create new document (IText)
    Document outdoc = new Document(PageSize.A4);

    // Seek to Stream start and create Reader for input PDF
    m.Seek(0, SeekOrigin.Begin);
    PdfReader inputPdfReader = new PdfReader(sourcePdfStream);

    // Seek to Stream start and create Reader for destination PDF
    m.Seek(0, SeekOrigin.Begin);
    PdfReader destinationPdfReader = new PdfReader(destinationPdfStream);

    // Create a PdfWriter from for new a pdf destination stream
    // You should write into a new stream here!
    Stream processedPdf = new MemoryStream();
    PdfWriter pdfw = PdfWriter.GetInstance(outdoc, processedPdf);

    // do not close stream if we've read everything
    pdfw.CloseStream = false;

    // Open document
    outdoc.Open();

    // get number of pages
    int numPagesIn = inputPdfReader.NumberOfPages;
    int numPagesOut = destinationPdfReader.NumberOfPages;

    int max = numPagesIn;

    // Process max number of pages
    if (max<numPagesOut)
    {
        throw new Exception("Impossible - different number of pages");
    }
    int i = 0;

    // Process Pdf pages
    while (i < max)
    {
        // Import pages from corresponding reader
        PdfImportedPage pageIn = writer.inputPdfReader(reader, i);
        PdfImportedPage pageOut = writer.destinationPdfReader(reader, i);

        // Get named destinations (annotations
        List<Annotations> toBeAdded = ParseInAndOutAndGetAnnotations(pageIn, pageOut);

        // add your annotations
        foreach (Annotation anno in toBeAdded) pageOut.Add(anno);

        // Add processed page to output PDFWriter
        outdoc.Add(pageOut);
    }

    // PDF creation finished
    outdoc.Close();

    // your new destination stream is processedPdf
    return processedPdf;
}

ParseInAndOutAndGetAnnotations（页面调，换页）的实现需要以反映您的注解。

The implementation of ParseInAndOutAndGetAnnotations(pageIn, pageOut) needs to reflect your annotations.

下面是注释的一个很好的例子：<一href="http://www.java2s.com/Open-Source/Java-Document/PDF/pdf-itext/com/lowagie/text/pdf/internal/PdfAnnotationsImp.java.htm" rel="nofollow">http://www.java2s.com/Open-Source/Java-Document/PDF/pdf-itext/com/lowagie/text/pdf/internal/PdfAnnotationsImp.java.htm

Here is a good example with annotations: http://www.java2s.com/Open-Source/Java-Document/PDF/pdf-itext/com/lowagie/text/pdf/internal/PdfAnnotationsImp.java.htm

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