android - 返回绑定(bind)数据或回收器 View 问题

Question

在我的 fragment 中，我有一些图像和 View ，它们通过绑定(bind)数据来获取它们的值，并且在它们下方是一个 RecyclerView。图像和 TextView 显示成功，但我的 Recyclerview 不会显示。如果我只返回我的 View ，则 RecyclerView 会显示，但绑定(bind)的数据不会。我想查看他们两个。

[ ]

class DetailFragment : Fragment(), LessonRecyclerAdapter.LessonItemListener {

    private lateinit var viewModel: SharedViewModel
    private lateinit var recyclerView: RecyclerView

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val view = inflater.inflate(R.layout.fragment_detail, container, false)
        recyclerView = view.findViewById(R.id.lessonRecyclerView)
        navController = Navigation.findNavController(requireActivity(), R.id.nav_host )

        viewModel = ViewModelProvider(requireActivity()).get(SharedViewModel::class.java)
        viewModel.lessonData.observe(viewLifecycleOwner, Observer {
            val adapter =
                LessonRecyclerAdapter(
                    it,
                    this
                )
            recyclerView.adapter = adapter
        })

        // return binding data
        val binding = FragmentDetailBinding.inflate(inflater, container, false)
        binding.lifecycleOwner = this
        binding.viewModel = viewModel
        return binding.root
        //return view
    }

Answer 1

如您所见，有两种充气，一种用于绑定(bind)，另一种用于查看(用于 recyclerview 设置)。简单的解决方法是直接使用recyclerview从绑定(bind)变量将列表设置为:

private lateinit var binding: FragmentDetailBinding

override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        navController = Navigation.findNavController(requireActivity(), R.id.nav_host )

        viewModel = ViewModelProvider(requireActivity()).get(SharedViewModel::class.java)

        binding = FragmentDetailBinding.inflate(inflater, container, false)
        binding.lifecycleOwner = this
        binding.viewModel = viewModel

        viewModel.lessonData.observe(viewLifecycleOwner, Observer {
            val adapter =
                LessonRecyclerAdapter(
                    it,
                    this
                )
            // directly access the view using ids                
            binding.lessonRecyclerView.adapter = adapter
        })

        return binding.root
    }

另一种选择是 use binding adapters使用实时数据设置适配器并将数据传递给适配器。