使用lifeCycle几大步骤

1.activity 或者fragment 实现LifecycleOwner 接口

2.在activity 或者fragment里面添加成员变量 

LifecycleRegistry lifecycleRegistry =new LifecycleRegistry(this);

3.实现LifecycleOwner  的getLifecycle方法，里面返回 lifecycleRegistry ；

@Override public Lifecycle getLifecycle() { return lifecycleRegistry; }

4.定义一个类，实现LifecycleObserver接口。用于接收生命周期的回调和处理

public class MyLocationListenerObserver implements LifecycleObserver { 

@OnLifecycleEvent(Lifecycle.Event.ON_RESUME)public void onResume() { Log.i(TAG, "MyLocationListenerObserver--->onResume"); }

@OnLifecycleEvent(Lifecycle.Event.ON_PAUSE) public void onPause() { Log.i(TAG, "MyLocationListenerObserver--->onPause"); }  

@OnLifecycleEvent(Lifecycle.Event.ON_STOP)  public void onStop() { Log.i(TAG, "MyLocationListenerObserver--->onStop"); }

}

5.在合适的地方添加观察者，一般在activity或者fragment的onCreate()

getLifecycle().addObserver(new MyLocationListenerObserver());