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Android 如何让LifecycleOwner参与可穿戴活动?_Android_Kotlin_Android Room_Android Livedata - Fatal编程技术网

Android 如何让LifecycleOwner参与可穿戴活动?

Android 如何让LifecycleOwner参与可穿戴活动?,android,kotlin,android-room,android-livedata,Android,Kotlin,Android Room,Android Livedata,当我尝试使用WearableActivity中的LiveData时,我遇到了一个问题: val livedata = ... val observer = ... livedata.observe(this, observer) 它在我使用活动扩展AppCompativeActivity时起作用,但看起来WearableActivity并没有实现LifecycleOwner接口,尽管它有一个生命周期,不是吗?(观察方法要求LifecycleOwner作为第一个参数)。如何使其工作?官方网站上显

当我尝试使用WearableActivity中的LiveData时,我遇到了一个问题:

val livedata = ...
val observer = ...
livedata.observe(this, observer)

它在我使用活动扩展AppCompativeActivity时起作用,但看起来WearableActivity并没有实现LifecycleOwner接口,尽管它有一个生命周期,不是吗?(观察方法要求LifecycleOwner作为第一个参数)。如何使其工作?

官方网站上显示的最新方法是扩展
androidx.fragment.app.FragmentActivity
并实现
AmbientModeSupport.AmbientCallbackProvider

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // setContentView will be the same as before
    setContentView(R.layout.activity_main)

    // Initialize yourCustomObserver here or have it injected

    // FragmentActivity has getLifeCycle() so you get it for free
    getLifeCycle().addObserver(yourCustomObserver);
}
就这样,您不需要手动更新LifecycleOwner(又名活动)生命周期状态

先前的答复 继Karan Modi之前的评论之后,您可以根据lifecycle文档中的指南实现自己的
getLifeCycle()

具体而言,您可以实现自己的LifeCycleOwner,如图所示:

public class MyActivity extends WearableActivity implements LifecycleOwner {
    private LifecycleRegistry mLifecycleRegistry;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mLifecycleRegistry = new LifecycleRegistry(this);
        mLifecycleRegistry.markState(Lifecycle.State.CREATED);
    }

    @Override
    public void onStart() {
        super.onStart();
        mLifecycleRegistry.markState(Lifecycle.State.STARTED);
    }

    @NonNull
    @Override
    public Lifecycle getLifecycle() {
        return mLifecycleRegistry;
    }
}

希望这能有所帮助。

我推测,如果WearableActivity没有实现LifecycleOwner,那么您需要在代码中这样做,并重写getLifeCycle()方法。