''' <summary>
''' Copies all pages of source PDF document to the end of destination PDF document.
''' </summary>
''' <param name="srcPdfFileName">The filename of source PDF document.</param>
''' <param name="destPdfFileName">The filename of destination PDF document.</param>
Public Shared Sub CopyPagesFromOnePdfDocumentToAnother(srcPdfFileName As String, destPdfFileName As String)
    ' open source PDF document
    Using srcDocument As New Vintasoft.Imaging.Pdf.PdfDocument(srcPdfFileName)
        ' open destination PDF document
        Using destDocument As New Vintasoft.Imaging.Pdf.PdfDocument(destPdfFileName)
            ' get pages of source PDF document as array
            Dim srcDocumentPages As Vintasoft.Imaging.Pdf.Tree.PdfPage() = srcDocument.Pages.ToArray()

            ' append the array of PDF pages to the destination PDF document
            destDocument.Pages.AddRange(srcDocumentPages)

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

/// <summary>
/// Copies all pages of source PDF document to the end of destination PDF document.
/// </summary>
/// <param name="srcPdfFileName">The filename of source PDF document.</param>
/// <param name="destPdfFileName">The filename of destination PDF document.</param>
public static void CopyPagesFromOnePdfDocumentToAnother(string srcPdfFileName, string destPdfFileName)
{
    // open source PDF document
    using (Vintasoft.Imaging.Pdf.PdfDocument srcDocument = 
        new Vintasoft.Imaging.Pdf.PdfDocument(srcPdfFileName))
    {
        // open destination PDF document
        using (Vintasoft.Imaging.Pdf.PdfDocument destDocument = 
            new Vintasoft.Imaging.Pdf.PdfDocument(destPdfFileName))
        {
            // get pages of source PDF document as array
            Vintasoft.Imaging.Pdf.Tree.PdfPage[] srcDocumentPages = srcDocument.Pages.ToArray();

            // append the array of PDF pages to the destination PDF document
            destDocument.Pages.AddRange(srcDocumentPages);

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