Question

我正在使用一个简单的改装调用，该调用随后将更新数据，并且片段将通过视图模型对其进行观察。不幸的是，由于某种原因，它根本不起作用。就像“ postValue或setValue”不起作用或已经消失一样。

片段：

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mViewModel = ViewModelProviders.of(requireActivity()).get(MyViewModel.class);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
       ...
        subscribe();
        mViewModel.fetchList();

        return rootView;
    }

    private void subscribe() {
        mViewModel.getListObservable().observe(this, new Observer<List<MyObj>>() {
            @Override
            public void onChanged(@Nullable List<MyObj> objList) {
                ....
            }
        });
    }

MyViewModel：

 private LiveData<List<MyObj>> mListObservable = new MutableLiveData<>();

    private Repository repository;

    public MoviesViewModel(Application application) {
        super(application);
        repository = new Repository();
    }

    public void fetchList(){
        mListObservable = repository.getList();
    }

    public LiveData<List<MovieObj>> getListObservable(){
        return mListObservable;
    }

存储库：

public LiveData<List<MyObj>> getList(){

        final MutableLiveData<List<MovieObj>> data = new MutableLiveData<>();

        mServiceInterface.getData("en-US").enqueue(new Callback<MyResponseCustom>() {
            @Override
            public void onResponse(Call<MyResponseCustom> call, Response<MyResponseCustom> response) {
                data.postValue(response.body().getResult());
            }

            @Override
            public void onFailure(Call<MyResponseCustom> call, Throwable t) {

            }
        });

        return data;
    }

Answer 1

您对Repository MutableLiveData发表了文章，但遵守了MyViewModel LiveData。合并它们或仅使用一个

尝试一下

MyViewModel：

public LiveData<List<MyObj>> fetchList(){
   return repository.getList();
}

片段：

mViewModel.fetchList().observe(this, new Observer<List<MyObj>>(){...}

在LiveData上未收到数据更改

1 个答案: