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() + ")");
    }
}