如何在 Android 中旋转屏幕时禁用重新创建片段

Question

在我的应用程序中，我使用 NavigationComponent 显示 Fragments 并且我使用 ViewModel !
但是旋转屏幕重新创建片段并删除所有位置，再次调用 api 等等...

我的片段代码：

    @AndroidEntryPoint
class HomeFragment : Fragment() {
    //Binding
    private lateinit var binding: FragmentHomeBinding

    @Inject
    lateinit var genreAdapter: GenreAdapter

    @Inject
    lateinit var topMoviesAdapter: TopMoviesAdapter

    private val viewModel: HomeViewModel by viewModels()

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
        binding = FragmentHomeBinding.inflate(inflater, container, false)
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        //InitViews
        binding.apply {
            //Genres
            viewModel.genresList.observe(viewLifecycleOwner) {
                genreAdapter.differ.submitList(it)
                genresRecycler.initRecycler(
                    LinearLayoutManager(requireContext(), LinearLayoutManager.HORIZONTAL, false),
                    genreAdapter
                )
            }
            viewModel.loadGenresList()
            //Top movies
            viewModel.topMoviesList.observe(viewLifecycleOwner) {
                topMoviesAdapter.differ.submitList(it.data)
                topMoviesRecycler.initRecycler(
                    LinearLayoutManager(requireContext(), LinearLayoutManager.HORIZONTAL, false),
                    topMoviesAdapter
                )
                topMoviesRecycler.smoothScrollToPosition(4)
            }
            viewModel.loadTopMoviesList(1)
            //Loading
            viewModel.loading.observe(viewLifecycleOwner) {
                if (it) {
                    homeLoading.showInvisible(true)
                } else {
                    homeLoading.showInvisible(false)
                }
            }
        }
    }
}

ViewModel 代码：

    @HiltViewModel
class HomeViewModel @Inject constructor(private val repository: HomeRepository) : ViewModel() {

    val genresList = MutableLiveData<List<ResponseGenres.ResponseGenresItem>>()
    val topMoviesList = MutableLiveData<ResponseMovies>()
    val loading = MutableLiveData<Boolean>()

    fun loadGenresList() = viewModelScope.launch {
        val response = repository.genresList()
        if (response.isSuccessful) {
            genresList.postValue(response.body())
        }
    }

    fun loadTopMoviesList(id: Int) = viewModelScope.launch {
        loading.postValue(true)
        val response = repository.topMoviesList(id)
        if (response.isSuccessful) {
            topMoviesList.postValue(response.body())
        }
        loading.postValue(false)
    }
}

如何修复它并禁用重新创建片段？

Answer 1

我建议避免使用 API 的 re-call，但从未想过禁用在片段中重新创建片段，因为这是一个 Android 架构。

简单的，重写Fragment中的onCreate()方法，将调用API的逻辑移到里面。

viewModel.loadGenresList()

这将调用一次，因为 onCreate() 即使在屏幕旋转后也只创建一次

如何在 Android 中旋转屏幕时禁用重新创建片段

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