七大生命周期方法：
onCreate、onStart、onResume、onRestart、onPause、onStop、onDestroy
对应官网图：
在此基础上补充：
1.onWindowFocusChanged：当Window当前的活动获得或失去焦点时调用
2.onUserLeaveHint：当活动即将作为用户选择的结果进入后台时调用
3.onNewIntent：启动一个已存在的SingleTop或SingleTask模式的Activity时调用
4.onSaveInstanceState：如果Activity可能被系统杀死时调用
5.onRestoreInstanceState：Activity确实被系统杀死时调用
各种操作下回调方法的顺序：
1.App正常启动：
onCreate->onStart->onResume->onWindowFoucusChanged
2.启动后屏幕熄灭/Home返回App：
onPause->onSaveInstanceState->onStop->onWindowFocusChanged
3.屏幕重新亮起：
onRestart->onStart->onResume->onWindowFocusChanged
4.启动后按下Home键：
onUserLeaveHint->onPause->onWindowFocusChanged->onSaveInstanceState->onStop
5.App正常关闭：
onWindowFoucusChanged->onPause->onStop->onDestroy
6.ActivityA启动ActivityB(Standard模式)：
ActivityA：onUserLeaveHint->ActivityA：onPause->ActivityA：onWindowFocusChanged->ActivityB：onCreate->ActivityB：onStart->ActivityB：onResume->ActivityB：onWindowFocusChanged->ActivityA：onSaveInstanceState->ActivityA：onStop
7.ActivityB回退ActivityA(startActivity启动)：
ActivityB：onPause->ActivityA：onRestart->ActivityA：onStart->ActivityA：onResume->ActivityA：onWindowFocusChanged->ActivityB：onWindowFocusChanged->ActivityB：onStop->ActivityB：onDestroy
8.ActivityB回退ActivityA(startActivityForResult启动)：
ActivityB：onPause->ActivityA：onActivityResult->ActivityA：onRestart->ActivityA：onStart->ActivityA：onResume->ActivityA：onWindowFocusChanged->ActivityB：onWindowFocusChanged->ActivityB：onStop->ActivityB：onDestroy
9.ActivityB启动ActivityB(SingleTask/SingleTop模式)：
onPause->onNewIntent->onResume
10.旋转屏幕：
onPause->onSaveInstanceState->onStop->onDestroy->onCreate->onStart->onRestoreInstanceState->onResume->onWindowFocusChanged
11.<activity>配置android:configChanges="keyboardHidden|orientation|screenSize"后旋转屏幕：onConfigurationChanged （最好3个都配置，否则不能适配所有机型或sdk版本）