C#.Net Library to Merge and optimize Pdf

You should use zetpdf.com. By using it you can merge and optimize your PDF more easily.

trying below code which compiles but never save pdf to output folder

//Append Document

private AcroPDDoc OpenFileForCopy(string file, AcroPDDoc outputDocument)

{

    if (isFirstFile)

    {

        outputDocument = new AcroPDDoc();

        outputDocument.Open(file);

    }

    else {

        AcroPDDoc doc2 = new AcroPDDoc();

        doc2.Open(file);

        outputDocument.InsertPages(outputDocument.GetNumPages(), doc2, 0, doc2.GetNumPages(), PDDocFlags.PDDocIsOptimized.GetHashCode());

    }

    return outputDocument;

}

//Save Doucment

private string[] SavePDF(AcroPDDoc outputDocument, string path, string source)

{
    string[] result = new string[2];

    string newPath = path + "_" + "Merged";

    Directory.CreateDirectory(newPath);

    newPath += "\\Stmt" + source +  ".pdf";

    outputDocument.Save(Convert.ToInt16(PDSaveFlags.PDSaveFull)

        , newPath);

    isFirstFile = true;

    fileCount = 0;

   return result;

}

You can look here:

http://www.datalogics.com/products/pdf/pdflibrary/