Sample Code VB.NET
Imports SelectPdf Namespace Controllers Public Class ModifyExistingPdfController Inherits Controller ' GET: ModifyExistingPdf Public Function Index() As ActionResult Return View() End Function <HttpPost> Public Function SubmitAction(collection As FormCollection) As ActionResult ' the initial file Dim file As String = Server.MapPath("~/files/doc1.pdf") ' load the pdf document Dim doc As New PdfDocument(file) ' add a new page to the document Dim page As PdfPage = doc.AddPage() ' create a new pdf font (component standard font) Dim font As PdfFont = doc.AddFont(PdfStandardFont.Helvetica) font.Size = 20 ' create text element and add it to the new page Dim text As New PdfTextElement(100, 100, "Sample text added to an existing pdf document.", font) page.Add(text) ' save pdf document Dim pdf As Byte() = doc.Save() ' close pdf document doc.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