C# code -Compare 2 pdf and give output as 2 pdfs with color

anoop gs

I have 2 pdf files pdf1 and pdf 2.I want to compare both pdf and should give result as 2 pdf outputs.

The 2 output pdf ,the changes should be highlighted in some color.say for output 1 -red color and output 2 pdf-green color for the change

Eg: input pdf 1 - text is :- I am anoop

input pdf 2 - text is :- I am aneesh

so the output should be as follows:

output pdf 3: I am anoop

output pdf 3: I am aneesh

means text anoop is changed to aneesh.So anoop in red color and aneesh in green color. Please provide the c# code for this.

6 Replies

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Satya Karki5y ago
You use use following code with PDFSharp.
using (PdfDocument one = PdfReader.Open("file1.pdf", PdfDocumentOpenMode.Import))
using (PdfDocument two = PdfReader.Open("file2.pdf", PdfDocumentOpenMode.Import))
using (PdfDocument outPdf = new PdfDocument())
{
    CopyPages(one, outPdf);
    CopyPages(two, outPdf);

    outPdf.Save("file1and2.pdf");
}

void CopyPages(PdfDocument from, PdfDocument to)
{
    for (int i = 0; i < from.PageCount; i++)
    {
        to.AddPage(from.Pages[i]);
    }
}
Rijwan Ansari5y ago
You can try this as well.
using PdfSharp;
using PdfSharp.Pdf;
using PdfSharp.Pdf.IO;

public static void MergePDFs(string targetPath, params string[] pdfs) {
    using(var targetDoc = new PdfDocument()){
        foreach (var pdf in pdfs) {
            using (var pdfDoc = PdfReader.Open(pdf, PdfDocumentOpenMode.Import)) {
                for (var i = 0; i < pdfDoc.PageCount; i++)
                    targetDoc.AddPage(pdfDoc.Pages[i]);
            }
        }
        targetDoc.Save(targetPath);
    }
}
params string[] pdfs is array of multiple pdfs path.
Regards
Rijwan
Rijwan Ansari5y ago
Hi,

check this article.
https://www.c-sharpcorner.com/article/merge-pdf/
Marvin Reid5y ago
You can find the differences of text from two PDFs using the CompareText method in the DocumentComparer class of the LEADTOOLS SDK. Once you compare the two, the TextDifference object can be used to get access to the DifferenceOperation enumeration which will allow you to find the changes made between the two files. You can try building on the following code for this:
var doc1 = DocumentFactory.LoadFromFile(@"D:\compare-original.pdf", new LoadDocumentOptions());
var doc2 = DocumentFactory.LoadFromFile(@"D:\compare-modified.pdf", new LoadDocumentOptions());

var textList = new List()
{
doc1.Pages.First().GetText(),
doc2.Pages.First().GetText()
};

var comparer = new DocumentComparer();
var diffs = comparer.CompareText(textList);
foreach (TextDifference diff in diffs)
{
diff.Operation = DifferenceOperation.Insert;
Console.WriteLine($"Operations: {diff.Operation}");
Console.WriteLine($"Text: {diff.Text}");
Console.WriteLine("--------");
}
https://www.leadtools.com/help/sdk/v21/dh/dc/documentcomparer-comparetext.html
https://www.leadtools.com/help/sdk/v21/dh/dc/textdifference.html
Leon D6y ago
Comparing PDFs is not an easy task, but you can try Spire.PDF for .NET library to extract text from PDFs and then compare the output.

https://www.e-iceblue.com/Tutorials/Spire.PDF/Spire.PDF-Program-Guide/How-to-Extract-Text-from-PDF-Document-with-C-/VB.NET.html
YaminiKumar Boyapati6y ago
May be we can use iTextSharp working around on PDF's