join a PDF to multiple PDFs with c#

Question

How about guys I need your help to program an application in c #. I have a folder that is constantly fed with documents and we must always add them manually, something that is complicated by the large number of files so I wanted to program something that allows me to join a pdf document to other files and I would like to know if there is a library for c#, c++ or .NET to allow me to do this. I attach a screenshot of the idea.

I was looking on the internet but I only find guides to join two documents and it is not what I am looking for

I hope you can help me

Answer 1

Hi there, I suggest that you can use Spire.PDF for .NET (available on NuGet) to do this job. Spire.PDF is a C# class library for creating and manipulating PDF documents on .NET platform.

Below is the code example for your referenece.

using System.IO;
using Spire.Pdf;

namespace MergeFiles
{
    class Program
    {
        static void Main(string[] args)
        {
            //Specify source file  
            string sourceFile = @"C:\Users\Administrator\Desktop\source.pdf";
            //Get files to merge in the "ToMerge" folder
            string[] filesToMerge = Directory.GetFiles(@"C:\Users\Administrator\Desktop\ToMerge");
            //Specify the output folder
            string outputFolder = @"C:\Users\Administrator\Desktop\Merged\";
            //Create a new document
            PdfDocumentBase newPdf;
            //Traverse all files in the "ToMerge" folder
            for (int i = 0; i < filesToMerge.Length; i++)
            {
                //Merge the source file "A" and another file in the "ToMerge" folder
                newPdf = PdfDocument.MergeFiles(sourceFile, filesToMerge[i]);
                //Save the document to a different PDF file
                string fileName = string.Format("Output-{0}.pdf", i + 1);
                newPdf.Save(outputFolder + fileName, FileFormat.PDF);            
            }
        }
    }
}

Answer 2

Try iText 7, also know as iTextSharp
iText 7

Answer 3

@Anonymous , as others said, you could use iTextSharp to join a pdf to multiple PDFs in c#.

Based on the code I have written from the link 4 PDF file marge to 1 PDF , I made some changes and the following code can get what you want.

static void Main(string[] args)  
        {  
            string sourcefile = "D:\\PDF\\A.pdf";  
            string[] file = { "D:\\PDF\\B.pdf", "D:\\PDF\\C.pdf", "D:\\PDF\\D.pdf" };  
            MergePDFs(file,sourcefile);  
             
        }  
  
        public static void MergePDFs(string []addedfilename,string sourcefilename)  
        {  
            foreach (var item in addedfilename)  
            {  
                string targetfilename = "";  
                if(item.Contains("B.pdf"))  
                {  
                    targetfilename ="D:\\PDF\\E.pdf";  
                }  
                if (item.Contains("C.pdf"))  
                {  
                    targetfilename ="D:\\PDF\\F.pdf";  
                }  
                if (item.Contains("D.pdf"))  
                {  
                    targetfilename ="D:\\PDF\\G.pdf";  
                }  
                using (FileStream stream = new FileStream(targetfilename, FileMode.Create))  
                {  
                    Document document = new Document();  
                    PdfCopy pdf = new PdfCopy(document, stream);  
                    PdfReader reader = null;  
                    try  
                    {  
                        document.Open();  
                        reader = new PdfReader(sourcefilename);  
                        pdf.AddDocument(reader);  
                        reader = new PdfReader(item);  
                        pdf.AddDocument(reader);  
                        reader.Close();  
                          
                    }  
                    catch (Exception)  
                    {  
                        if (reader != null)  
                        {  
                            reader.Close();  
                        }  
                    }  
                    finally  
                    {  
                        if (document != null)  
                        {  
                            document.Close();  
                        }  
                    }  
                }  
            }  
        }  

Note: Please don't forget to install nuget-package iTextSharp.

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Answer 4

Docotic.Pdf library is a good alternative to the provided solution. Here is a code that merges multiple PDF files:

string[] filesToMerge = ..;
using var pdf = new PdfDocument();
foreach (string file in filesToMerge)
    pdf.Append(file);
// Remove the empty page added by the PdfDocument() call
pdf.RemovePage(0);
pdf.Save(pathToFile);

There are advanced merging options. The Merge PDF documents in C# and VB.NETarticle describes them.