前台应用程序处于什么状态但几分钟后显示为非活动状态？

Question

I'm developing an iPad app, and I noticed a state where app appears to be sleep in foreground.

The step to reproduce:

1. Set screen on time for 15 minutes.
2. Launch the app and wait for more than 5 minutes
3. When click the screen after 5 minutes, the app appears to be inactive for 2 seconds and not accepting new events.
4. After 2 seconds, the app registers that touch and begin responding

I'm wondering is the app goes from active foreground to inactive foreground after certain amount of inactivity in foreground?

If so, how long will it take for the app to go to that foreground inactive state. Is there any delegate or notifications that listens to that event happening?

Answer 1

Probably app is Inactive state - The app is running in the foreground, but not receiving events. An iOS app can be placed into an inactive state, for example, when a call or SMS message is received.