Question

我对以下代码段有疑问。

MainActivity.Java

public class MainActivity extends AppCompatActivity implements LifecycleOwner,LifeCycleComponant {

    private static final String TAG =MainActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getLifecycle().addObserver(new MyObserver());

    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.d(TAG, "onPause: ");
        getState();
    }

    @Override
    public void getState() {
        Log.d(TAG, "getState: "+getLifecycle().getCurrentState());
    }
}

MyObserver.Java

    public class MyObserver implements LifecycleObserver {
    private static String TAG=MainActivity.class.getSimpleName();
    private LifeCycleComponant lifeCycleComponant;
    @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
    public void myOnCreate(){
        Log.d(TAG, "myOncreate: ");
        lifeCycleComponant=new MainActivity();
        lifeCycleComponant.getState();
    }
    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    public void myOnDestroy(){
        Log.d(TAG, "myOnDestroy: ");
        lifeCycleComponant.getState();
        lifeCycleComponant=null;
    }
    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    public void myOnResume(){
        Log.d(TAG, "myOnResume: ");
        lifeCycleComponant.getState();
    }
    @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
    public void myOnPause(){
        Log.d(TAG, "myOnPause: ");
        lifeCycleComponant.getState();

    }
}

每当我调用lifeCycleComponant.getState（）时，它只返回INITIALIZED。但是当我从MainActivit.onPause（）方法调用它时，它给出了正确的答案。

Answer 1

lifeCycleComponant=new MainActivity();

将创建一个新的Activity，它将处于初始化状态，并且不会链接到前台运行的Activity。

您无需访问Observer中的当前状态，因为它将根据相应的Lifecycle.Event

触发

getCurrentState（）仅返回“INITIALIZED”

1 个答案: