如何手动刷新实时数据

Question

我不了解如何手动实施刷新实时数据。在我的情况下，用户经常面临连接问题，因为回收者视图不显示任何数据。我想给滑动刷新布局刷新实时数据。 这是我的数据源

class CourseRemoteDataSource @Inject constructor(private val service: ApiService) :
    BaseDataSource() {

    suspend fun fetchFeaturedCourses() =
        getResult {
            service.getFeaturedCourses(
                SharedPreferencesManager(App.getContext()).getToken()!!
            )
        }
}

这是存储库

@Singleton
class CourseRepository @Inject constructor(
    private val dao: CourseDao,
    private val remoteSource: CourseRemoteDataSource
) {
      val featuredCourses = resultLiveData(
        databaseQuery = { dao.getFeaturedCourses() },
        networkCall = { remoteSource.fetchFeaturedCourses() },
        saveCallResult = { dao.insertFeaturedCourses(it.result) }
    )
}

这是我的视图模型

class FeaturedCoursePageViewModel @Inject constructor(private val repository: CourseRepository) :
    ViewModel() {
    val courses = repository.featuredCourses

    override fun onCleared() {
        super.onCleared()
    }
}

这是我的片段

class FeaturedCoursePageFragment : Fragment(), Injectable {

    @Inject
    lateinit var viewModelFactory: ViewModelProvider.Factory
    private lateinit var viewModelFeatured: FeaturedCoursePageViewModel
    private lateinit var binding: FragmentCourseFeaturedBinding
    private lateinit var adapter: FeaturedCoursePageAdapter

    companion object {
        fun newInstance(): Fragment {
            val args = Bundle()
            val fragment = FeaturedCoursePageFragment()
            fragment.arguments = args
            return fragment
        }
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        viewModelFeatured = injectViewModel(viewModelFactory)

        binding = FragmentCourseFeaturedBinding.inflate(inflater, container, false)
        context ?: return binding.root

        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        adapter = FeaturedCoursePageAdapter()
        binding.recyclerViewCourseFeatured.adapter = adapter

        binding.swipeRefreshLayoutCourseFeatured.setColorSchemeResources(R.color.colorPrimary)
        binding.swipeRefreshLayoutCourseFeatured.setOnRefreshListener {
            subscribeInterface()
        }

        subscribeInterface()
    }

    private fun subscribeInterface() {
        viewModelFeatured.courses.observe(viewLifecycleOwner,
            { result ->
                when (result.status) {
                    Result.Status.SUCCESS -> {
                        binding.progressBarCourseFeatured.hide()
                        result.data?.let {
                            if (it.isEmpty()) binding.linearLayoutEmptyPlaceholder.show() else binding.linearLayoutEmptyPlaceholder.hide()
                            adapter.submitList(it)
                        }
                        binding.swipeRefreshLayoutCourseFeatured.stop()
                    }
                    Result.Status.LOADING -> {
                        binding.progressBarCourseFeatured.show()
                        binding.linearLayoutEmptyPlaceholder.hide()
                        binding.swipeRefreshLayoutCourseFeatured.start()
                    }
                    Result.Status.ERROR -> {
                        binding.progressBarCourseFeatured.hide()
                        if (result.code == 204) {
                            binding.linearLayoutEmptyPlaceholder.show()
                        }
                        binding.swipeRefreshLayoutCourseFeatured.stop()
                    }
                }
            })
    }
}

我尝试了一些技巧，但livedata返回了旧数据。 在此之前，请帮助我解决这个关键问题。