Touch screen and locked phone

Is it possible to get the coordinates of your finger while the phone is locked 开发者_JS百科and the software is working at background ?

No, no more than you can "get the coordinates of your finger" at any other time when your "software is working at background". If you are not on the screen, you cannot receive touch events.

Typically the OEMs will put the touchscreen hardware to sleep when the device is locked to save power. This means the touch screen won't detect your touch when the device is locked. Aside from that, I'm pretty sure the Android life cycle wouldn't let you do much anyway.