Activity生命周期
1、Activity启动running:系统先调用onCreate - onStart - onResume,Activity进入运行状态;
2、Activity暂停:activity被覆盖,系统会调用onPause - onStop 暂停当前activity;
3、用户返回Activity:系统先调用 onRestart - onStart - onResume,再进入运行状态;
4、用户退出当前Activity:系统先调用 onPause - onStop - onDestory,结束当前Activity;
参考: