Sample Code VB.NET
Imports SelectPdf Namespace Controllers Public Class PdfMergeController Inherits Controller ' GET: PdfMerge Public Function Index() As ActionResult Return View() End Function <HttpPost> _ Public Function SubmitAction(collection As FormCollection) As ActionResult ' the 2 initial files Dim file1 As String = Server.MapPath("~/files/doc1.pdf") Dim file2 As String = Server.MapPath("~/files/doc2.pdf") ' load the 2 pdf documents Dim doc1 As New PdfDocument(file1) Dim doc2 As New PdfDocument(file2) ' create a new pdf document Dim doc As New PdfDocument() ' add the pages of those 2 documents to the new document doc.Append(doc1) doc.Append(doc2) ' save pdf document Dim pdf As Byte() = doc.Save() ' close pdf document doc.Close() doc1.Close() doc2.Close() ' return resulted pdf document Dim fileResult As FileResult = New FileContentResult(pdf, "application/pdf") fileResult.FileDownloadName = "Document.pdf" Return fileResult End Function End Class End Namespace