Merge PDF files in C#

In this article, I am going to show you how to merge multiple PDF files programmatically using Merge_File method and easy PDF SDK. This C# sample program demonstrates how to merge PDF pages using the PDFProcessor API.

The file names are assumed to be in the array files[]. The merged file is saved under “outFileName”

private void Merge_File(string[] files, string outFileName)
{
    try
    {
        PDFProcessor oPDFProcessor = new PDFProcessor();
            // loop over all the files, which are concatenated one by one
            string inFileName = files[0];
    
        for(int i = 1; i < files.Length; i++)
        {
            oPDFProcessor.Merge(inFileName, files[i], outFileName);         
            inFileName = outFileName;
        }               
            
        MessageBox.Show(files.Length.ToString() + " files merged!");
    }
    catch(System.Runtime.InteropServices.COMException err)
    {
        MessageBox.Show(err.Message + " (" + err.ErrorCode.ToString() + ")");
    }
}

Comments

[Atir Tahir]

This is quite helpful but what if we want one-stop solution for different file formats. Like if I want to merge Word files or Excel files using single API? At this point, GroupDocs.Merger for .NET API allows you to join two Word files or two Excel spreadsheet etc using same piece of code.
See how simple is this:

	// For complete examples and data files, please go to https://github.com/groupdocs-merger/GroupDocs.Merger-for-.NET
	string sourceFile1 = CommonUtilities.fileOne + fileOne;
	string sourceFile2 = CommonUtilities.fileTwo + fileTwo;
	// Preparing.
	Stream openFile1 = new FileStream(sourceFile1, FileMode.Open);
	Stream openFile2 = new FileStream(sourceFile2, FileMode.Open);
	List<Stream> documentStreams = new List<Stream>();
	documentStreams.Add(openFile1);
	documentStreams.Add(openFile2);
	// Main method.
	DocumentResult result = new DocumentHandler().Join(documentStreams);
	Stream documentStream = result.Stream;
	var fileStream = File.Create(CommonUtilities.outputPath + "OutPut." + result.FileFormat);
	documentStream.CopyTo(fileStream);
	documentStream.Close();

view raw Examples-CSharp-GroupDocs.Merger.Examples.CSharp-DocsManipulation-JoinDocumentsOfUnknownFormat.cs hosted with ❤ by GitHub