private void PrintDocument()
        {
            if (pdfViewer1.Document.FormFill != null)
                pdfViewer1.Document.FormFill.ForceToKillFocus();

            var printDoc = new PdfPrintDocument(pdfViewer1.Document);

            printDoc.AutoRotate = true;
     
            using (var dlg = new PrintDialog())
            {
                dlg.Document = printDoc;

                dlg.Document.PrintPage += Document_PrintPage;

                dlg.AllowCurrentPage = true;

                dlg.AllowSomePages = true;

                DialogResult result = dlg.ShowDialog();

                if (result == DialogResult.OK)

                    dlg.Document.Print();
            }
        }