如何在Non-FragmentActivity上使用ViewModelProviders.of（）获取ViewModel？

Question

private void subscribeToModel() {
    final MyViewModel model = ViewModelProviders.of(this)
            .get(MyViewModel.class);

    // Update the list when the data changes
    model.getItems().observe(this, new Observer<List<Item>>() {
        @Override
        public void onChanged(@Nullable List<Item> items) {
            // Do something useful
        }
    });
}

This code above works well on 'AppCompatActivity' or 'FragmentActivity'. However, it does not work on another type of Activity (eg. for me: GvrActivity). ViewModelProviders.of() is expecting 'FragmentActivity'.

Is there another way to observe the DB?

As for the DB, I am using ROOM.

Answer 1

Answering my own question.

Observing a Room database is the solution. Thanks CommonsWare.

Here's full solution:

private void subscribeToModel() {
    final DatabaseCreator databaseCreator = DatabaseCreator.getInstance();
    LiveData<List<Item>> itemLiveData = databaseCreator.getDatabase().itemDao().getAllLiveData();
    if(itemLiveData != null) {
        itemLiveData.observe(this, new Observer<List<Item>>() {
            @Override
            public void onChanged(@Nullable List<Item> items) {
                // Do something useful
            }
        });
    }
}