Android：当活动死亡时，计时器是孤立的

Question

I'm a relative Android newbie writing a timer application. I'm using a custom countdown timer class which is a member of the main activity class, and it spawns a Handler to run each second.

When I close the app, the main activity stops, but the timer continues to run in the background, as I want. The problem is that when the activity restarts, the original timer is now an orphan, and I can't find a way of re-attaching to it.

What's the best way of keeping a persistent connection to a timer object, even between activity restarts?

Answer 1

There are several different approaches.

• You can make use of the System's AlarmManager .
• You can make your own Service .
• You can make your TimerObject persist .

As I do not know your exact requirements, I suggest you follow the white rabbit links above and judge for yourself.

If you have to stick to the model you described above, maybe the third one is the best option for you.

Does this object actually do anything each second even with closed activity? Maybe it's enough to persist a reference timestamp and destroy the TimerObject/Handler on exit ( onPause ) and make a new one with the persisted state (if any) when starting the Activity?