''' <summary>
''' Swaps the first and the last pages of PDF document.
''' </summary>
''' <param name="pdfFileName">The filename of PDF document.</param>
Public Shared Sub SwapPages(pdfFileName As String)
    ' open PDF documnet
    Using document As New Vintasoft.Imaging.Pdf.PdfDocument(pdfFileName)
        ' get the collection of pages of PDF document
        Dim pages As Vintasoft.Imaging.Pdf.Tree.PdfPageCollection = document.Pages

        ' get the page count
        Dim pagesCount As Integer = pages.Count
        ' swap the first and the last pages
        pages.Swap(0, pagesCount - 1)

        ' save changes to a file
        document.SaveChanges()
    End Using
End Sub

/// <summary>
/// Swaps the first and the last pages of PDF document.
/// </summary>
/// <param name="pdfFileName">The filename of PDF document.</param>
public static void SwapPages(string pdfFileName)
{
    // open PDF documnet
    using (Vintasoft.Imaging.Pdf.PdfDocument document =
        new Vintasoft.Imaging.Pdf.PdfDocument(pdfFileName))
    {
        // get the collection of pages of PDF document
        Vintasoft.Imaging.Pdf.Tree.PdfPageCollection pages = document.Pages;

        // get the page count
        int pagesCount = pages.Count;
        // swap the first and the last pages
        pages.Swap(0, pagesCount - 1);

        // save changes to a file
        document.SaveChanges();
    }
}