Question

I have an application that has a user log in and log out. On a log in it tells my DataBase that the user is online. Problem I am having is that when the user doesnt use the app for a while and the processor kills my app is there a method or something where i can run my last piece of code to log them out? I looked at the android life cycle and i cannot use destroy because that only ties with that activity. Thanks!

Answer 1

I found a solution for this – not perfect but worked for me.

1.) Create a service to run in the background which is started when the first activity is created.

2.) Each activity binds to this service so it can “check-in” (i.e. it is alive and onPause) hasn’t been called)

3.) In each activity register a broadcast receiver that listens for an intent fired by the service on a regular basis.

4.) On receiving the chech-in intent, it calls a service method which basically lets the service now there is an activity that is still alive (I tent to only respond to the intent if it had windowFocus

5.) If there is a check-in the service sleeps and then re-requests a checkin, if there was no check-in it sleeps for a shorter period of time, before re-requesting a check-in, if none respond then the app logs out. (The reason for the second re-quest when no check-ins were found was to account for issues surrounding check-in during an activity transition, i.e. starting a new activity and closing the current one).

As I said this isn’t the nicest way to do it but seems to work for my needs so far.