Merge PDF files in C# and VB.NET

With PDF .Net, you can merge PDF files into one PDF file in your C# or VB.NET application.

A PDF page is a self-contained entity (its appearance is completely defined by its content stream and associated resources, and its annotations primarily define interactivity). As such, they can be easily cloned into other PDF files.

To merge PDF files, you simply need to clone all of their pages into a destination PDF file.

The following example shows how you can merge (concatenate) PDF files.

Complete code

using System;
using System.IO;
using SautinSoft;
using SautinSoft.Pdf;
using SautinSoft.Pdf.Content;

namespace Sample
    class Sample
        /// <summary>
        /// Merge PDF files.
        /// </summary>
        /// <remarks>
        /// Details: http://sautinsoft/products/pdf/help/net/developer-guide/merge-pdf-files.php
        /// </remarks>
        static void Main(string[] args)
            // Before starting this example, please get a free 30-day trial key:

            // Apply the key here:
            // PdfDocument.SetLicense("...");


        static void MergePdf()
            string[] inpFiles = new string[] {
                        Path.GetFullPath(@"..\..\..\Simple Text.pdf"),
                        Path.GetFullPath(@"..\..\..\Potato Beetle.pdf"),
                        Path.GetFullPath(@"..\..\..\Text and Graphics.pdf")};

            string outFile = Path.GetFullPath(@"Merged.pdf");

            // Create a new PDF document.
            using (var pdf = new PdfDocument())
                // Merge multiple PDF documents the new single PDF.
                foreach (var inpFile in inpFiles)
                    using (var source = PdfDocument.Load(inpFile))

            // Show the result.
            System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo(outFile) { UseShellExecute = true });


In the example above, you can see that the source PDF file is combined and the pages cloned into a new PDF.Net, which is then saved to a PDF file.

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