Q:
I would like to know how to get the current page number in continuous or facing mode.
A:
To get the page number of the page currently displayed on the screen at a given coordinate (i.e., under the pointer), you can use PDFViewCtrl.getPageNumberFromScreenPt() on each platform:
http://www.pdftron.com/pdfnet/mobile/docs/Android/pdftron/PDF/PDFViewCtrl.html#getPageNumberFromScreenPt%28double,%20double%29
http://www.pdftron.com/pdfnet/mobile/docs/iOS/src/interface_p_d_f_view_ctrl.html#a32559d23222428282cad0c32b0795f4e