Imports Bytescout.PDF

''' <summary>
''' This example demonstrates how to create a button that launches an external resource.
''' </summary>
Class Program

    Shared Sub Main()

        ' Create new document
        Dim pdfDocument = New Document()
        pdfDocument.RegistrationName = "demo"
        pdfDocument.RegistrationKey = "demo"

        ' If you wish to load an existing document uncomment the line below And comment the Add page section instead
        ' pdfDocument.Load(".\existing_document.pdf")

        ' Add page
        Dim page = New Page(PaperFormat.A4)
        pdfDocument.Pages.Add(page)

        ' Create button
        Dim button = New PushButton(20, 20, 120, 25, "button1")
        button.Caption = "Launch sample.txt"
        ' Create action that opens an external file
        Dim launchAction = New LaunchAction(IO.Path.GetFullPath("sample.txt"))
        button.OnActivated = launchAction
        page.Annotations.Add(button)

        ' Save document to file
        pdfDocument.Save("result.pdf")

        ' Cleanup 
        pdfDocument.Dispose()

        ' Open document in default PDF viewer app
        Process.Start("result.pdf")

    End Sub

End Class

sample.txt

1234567890
abcdefghijklmnopqrstuvwxyz