问题
When all services are stopped, all broadcast receivers finished their jobs and no activities are running. Will always Android kill the app process?
回答1:
Immediately? No. Your process will be a cached process, until such time as either your process is needed again or Android needs the system RAM for other processes.
See the documentation for more.
How long a process remains cached varies based on the amount of system RAM and how much activity is going on. It could be milliseconds. It might be seconds. It's possible it will live for minutes. It is rather unlikely to live for hours.
来源：https://stackoverflow.com/questions/44835752/is-app-process-always-killed-when-all-android-components-are-destroyed