如何从另一个活动与适配器进行通信？

Question

我在属于活动 A 的片段内有一个适配器，从该适配器我打开活动 B 中的元素的详细信息。我如何告诉活动 A 的适配器它必须更新该适配器的列表在活动 B 的片段中？

这是我在活动中使用的方法：

private fun setOnClickFavoriteListener(recipe: RecipesItem?) {
        binding?.recipeDetailContainerFavoriteButton?.setOnClickListener {
            if (recipe?.isFavorite == true) {
                isFavorite = false
                viewModel.setFavoriteRecipe(recipe.id, isFavorite)
                binding?.recipeDetailImgFavoriteButton?.setColorFilter(
                    ContextCompat.getColor(
                        this,
                        R.color.silver
                    )
                )
            } else {
                isFavorite = true
                viewModel.setFavoriteRecipe(recipe?.id, isFavorite)
                binding?.recipeDetailImgFavoriteButton?.setColorFilter(
                    ContextCompat.getColor(
                        this,
                        R.color.sunglo
                    )
                )
            }
        }
    }

这是我的适配器，它不在同一个活动中，所以它们之间没有通信：

class FavoritesAdapter(private val favorites: List<RecipesItem>) :
    RecyclerView.Adapter<FavoritesViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): FavoritesViewHolder {
        val binding = FavoritesRowBinding.inflate(
            LayoutInflater.from(parent.context),
            parent,
            false
        )
        return FavoritesViewHolder(binding)
    }

    override fun onBindViewHolder(holder: FavoritesViewHolder, position: Int) {
        holder.bind(favorites[position])
    }

    override fun getItemCount(): Int {
        return favorites.size
    }
}

class FavoritesViewHolder(private val binding: FavoritesRowBinding) :
    RecyclerView.ViewHolder(binding.root) {

    fun bind(recipesItem: RecipesItem) {
        binding.favoritesRowImgRecipeImage.load(recipesItem.imageURL)
        binding.favoritesRowLabelRecipeName.text = recipesItem.name
        binding.favoritesRowLabelTime.text = binding.root.context.getString(
            R.string.recipe_time,
            recipesItem.time
        )
        binding.favoritesRowLabelDifficult.text = recipesItem.difficult
        binding.root.setOnClickListener {
            val bundle = bundleOf(RECIPE_BUNDLE to recipesItem)
            val intent = Intent(binding.root.context, RecipeDetailActivity::class.java)
            intent.putExtras(bundle)
            binding.root.context.startActivity(intent)
        }
    }
}

我尝试将收藏夹列表的获取放在 onResume 中，但它做了一个奇怪的事情效果，它简要显示空列表图像，然后显示更新的列表：

@AndroidEntryPoint
class FavoritesFragment : Fragment() {

    private val viewModel: FavoritesViewModel by viewModels()
    private var binding: FragmentFavoritesBinding? = null

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

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        (activity as DashboardActivity).showToolbar(true)
        (activity as DashboardActivity).setToolbarTitle(getString(R.string.option_menu_favorite))
    }

    private fun initObservers() {
        viewModel.favoritesLiveData.observe(viewLifecycleOwner) { favorites ->
            if (favorites.isNullOrEmpty()) {
                binding?.favoritesRecyclerViewRecipes?.hide()
                binding?.favoritesGroupEmptyRecipes?.show()

            } else {
                binding?.favoritesRecyclerViewRecipes?.show()
                binding?.favoritesGroupEmptyRecipes?.hide()
                val adapter = FavoritesAdapter(favorites)
                binding?.favoritesRecyclerViewRecipes?.layoutManager = LinearLayoutManager(
                    context,
                    LinearLayoutManager.VERTICAL,
                    false
                )
                binding?.favoritesRecyclerViewRecipes?.adapter = adapter
            }

        }
    }

    override fun onResume() {
        super.onResume()
        viewModel.getFavoritesFromDatabase()
        initObservers()
    }

    override fun onDestroy() {
        binding = null
        super.onDestroy()
    }

Answer 1

从活动“A”片段中的适配器中，您可以像以前一样发送意图包中的项目。
然后，您可以从活动“B”处理该捆绑包并将该项目发送到活动“B”中的片段，然后该片段将在其适配器中呈现该项目。
我希望我正确理解你的问题