Android官方架构组件Lifecycle

Lifecycle 是一个类，它持有关于组件（如 Activity 或 Fragment）生命周期状态的信息，并且允许其他对象观察此状态。
使用：

1、Prestener继承LifecycleObserver接口

public interface IPresenter extends LifecycleObserver {
    @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
    void onCreate(@NonNull LifecycleOwner owner);

    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    void onDestroy(@NonNull LifecycleOwner owner);

    @OnLifecycleEvent(Lifecycle.Event.ON_ANY)
    void onLifecycleChanged(@NonNull LifecycleOwner owner, @NonNull Lifecycle.Event event);
}

public class BasePresenter implements IPresenter {

    private static final String TAG = "BasePresenter";


    @Override
    public void onCreate(@NonNull LifecycleOwner owner) {
        Log.d("tag", "BasePresenter.onCreate" + this.getClass().toString());
    }

    @Override
    public void onDestroy(@NonNull LifecycleOwner owner) {
        Log.d("tag", "BasePresenter.onDestroy" + this.getClass().toString());
    }

    @Override
    public void onLifecycleChanged(@NonNull LifecycleOwner owner, @NonNull Lifecycle.Event event) {

    }
}

public class MainPresenter extends BasePresenter {

}

将想要观察到Presenter的生命周期事件都列了出来，然后封装到BasePresenter 中，这样每一个BasePresenter 的子类都能感知到Activity容器对应的生命周期事件，并在子类重写的方法中，对应相应行为。

2、在Activity/Fragment容器中添加Observer

public class MainActivity extends AppCompatActivity {

    MainPresenter mainPresenter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Log.d("tag", "onCreate" + this.getClass().toString());
        mainPresenter = new MainPresenter();
        getLifecycle().addObserver(mainPresenter);
    }

    @Override
    protected void onDestroy() {
        Log.d("tag", "onDestroy" + this.getClass().toString());
        super.onDestroy();
    }
}

结果：

tag: onCreateclass com.example.administrator.myapplication.MainActivity
tag: BasePresenter.onCreateclass com.example.administrator.myapplication.MainPresenter

tag: BasePresenter.onDestroyclass com.example.administrator.myapplication.MainPresenter
tag: onDestroyclass com.example.administrator.myapplication.MainActivity