Android：为什么活动在onPause？

Question

I must to know if my Activity is displayed or not. I would to use the method onPause and onResume but I want to know also why the activity is in onPause.... There are 3 cases :

1. Activity in onPause because the display turn off
2. Activity in onPause because the user have clicked the home button
3. Activity in onPause because the user have clicked the home button and screen off

How can I do ? Thanks

EDIT : I resolved with this code :

ActivityManager activityManager = (ActivityManager)getContext().                .getSystemService(Context.ACTIVITY_SERVICE);
List<RunningTaskInfo> runningTasks = activityManager.getRunningTasks(Integer.MAX_VALUE));

Answer 1

* 1. * Activity in onPause because the display turn off and if any call appear : onPause() called

* 2. *Activity in onPause because the user have clicked the home button : onUserLeaveHint() called before onPause() if user press home button

* 3. *When user press Back key : onUserInteraction() called before onPause()

Answer 2

When You leave from one Activity to other Activity the activity from where you are leaving that activity onPause get called. If you want to experiment create all the function Inside the onStart call the other activity onPause of the First activity get called.

For more Information please go through by below link:

http://developer.android.com/guide/topics/fundamentals/activities.html