如何使用RxJava包装startActivityForResult？

implementation 'io.reactivex.rxjava2:rxjava:2.x.x'
implementation 'io.reactivex.rxjava2:rxandroid:2.x.x'

public Observable<ActivityResult> startActivityForResultObservable(Activity activity, Intent intent, int requestCode) {
    return Observable.create(emitter -> {
        // 创建一个ActivityResultListener来监听Activity的结果
        ActivityResultListener listener = new ActivityResultListener() {
            @Override
            public void onActivityResult(int resultCode, Intent data) {
                // 将结果发射给观察者
                emitter.onNext(new ActivityResult(resultCode, data));
                emitter.onComplete();
            }
        };

        // 注册ActivityResultListener
        MyActivityResultRegistry.getInstance().registerListener(listener);

        // 启动Activity
        activity.startActivityForResult(intent, requestCode);

        // 在Observable被取消订阅时，移除ActivityResultListener
        emitter.setCancellable(() -> MyActivityResultRegistry.getInstance().unregisterListener(listener));
    });
}

startActivityForResultObservable(activity, intent, requestCode)
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe(result -> {
        // 处理Activity的结果
        int resultCode = result.getResultCode();
        Intent data = result.getData();
        // ...
    });