How to detect scanner input in xamarin.forms

Hi,
in my app (targeting Android and iOS) I want to implement a new function to scan barcodes with a bluetooth barcode scanner. On my device the scanner is detected as a keyboard. Does someone know if it's possible to detect if an input comes from the screen keyboard or from an external keyboard like my scanner? My problem ist that everything works fine while the focus is inside an Entry. But there are some pages that don't containt an entry. In this case I want to handle the scanned barcode in the background and show another page.

Thanks a lot for any answer