Timer across the multiple activities

Question

i have an android app with several activities. I need to start a timer when the first activity starts and end the timer when the last activity starts and show the elapsed time. How can i use Asynctask to do this.

Answer 1

Subclass Application, declare a public static long started; which will be assigned to System.currentTimeMillis(); by the first Activity in onCreate() or onResume(). Have the last Activity read the value and calculate delta.
If you absolutely want to use AsyncTask (which I think is irrelevant in this case), you'll at least need a mediatory Service for that.