lateinit 属性适配器尚未初始化设置 RecyclerView 与 Fragment

Posted 2023-04-15

【中文标题】lateinit 属性适配器尚未初始化设置 RecyclerView 与 Fragment

【英文标题】：lateinit property adapter has not been initialized setting up RecyclerView with Fragment

【发布时间】：2020-06-08 15:09:18

【问题描述】：

我在将 RecyclerView 调整为片段时遇到问题。我有一个导航抽屉，它又具有一个 TabLayout，当我单击一个选项卡时，它会将我带到这个 RecyclerView。没办法适配，现在报“lateinit property adapter has not been initialized”的错误，但我试了上千种方法。

MainAdapter.kt

class MainAdapter(private val context: Context) : RecyclerView.Adapter<MainAdapter.MainViewHolder>() 


private var dataList = mutableListOf<Usuario>()

fun setListData(data:MutableList<Usuario>)
    dataList = data


override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MainViewHolder 
    val view = LayoutInflater.from(context).inflate(R.layout.item_row, parent, false)
    return MainViewHolder(view)


override fun getItemCount(): Int 
    return if(dataList.size > 0)
        dataList.size
    else
        0
    


override fun onBindViewHolder(holder: MainViewHolder, position: Int) 
    val user = dataList[position]
    holder.bindView(user)


inner class MainViewHolder(itemView: View): RecyclerView.ViewHolder(itemView)

    fun bindView(user: Usuario)
        Glide.with(context).load(user.imageUrl).into(itemView.circleImageView)
        itemView.txt_title.text = user.nombre
        itemView.txt_desc.text = user.descripcion 
    

FragmentNotification.kt

class NotificacionesFragment : Fragment()

private lateinit var adapter: MainAdapter
private lateinit var _view: View
private lateinit var rv: RecyclerView


override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
): View? 
    _view = inflater.inflate(R.layout.notificaciones, container, false)
   // val viewPager = x.findViewById<View>(R.id.viewPager) as ViewPager
    rv = _view.findViewById(R.id.rv) as RecyclerView

    rv.adapter = MainAdapter (requireContext())

    _view.rv.layoutManager = LinearLayoutManager(requireContext())
    _view.rv.adapter = adapter

    val dummyList = mutableListOf<Usuario>()
    dummyList.add(Usuario("lala","lala","lala"))

    adapter.setListData(dummyList)
    adapter.notifyDataSetChanged()

    return _view

【参考方案1】：

错误很明显：

lateinit 属性适配器尚未初始化

您从未设置此属性：

private lateinit var adapter: MainAdapter

您设置了rv.adapter，但绝不仅仅是adapter。相反，您可能打算这样做：

adapter = MainAdapter (requireContext())
rv.adapter = adapter

【讨论】：

你是最棒的！

【参考方案2】：

class NotificacionesFragment : Fragment()

private lateinit var adapter: MainAdapter
private lateinit var _view: View
private lateinit var rv: RecyclerView


override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
): View? 
    _view = inflater.inflate(R.layout.notificaciones, container, false)
   // val viewPager = x.findViewById<View>(R.id.viewPager) as ViewPager
    rv = _view.findViewById(R.id.rv) as RecyclerView

    adapter = MainAdapter (requireContext())

    _view.rv.layoutManager = LinearLayoutManager(requireContext())
    _view.rv.adapter = adapter

    val dummyList = mutableListOf<Usuario>()
    dummyList.add(Usuario("lala","lala","lala"))

    adapter.setListData(dummyList)
    adapter.notifyDataSetChanged()

    return _view