Recyclerview未显示kotlin[副本]

Question

recyclerview没有显示在屏幕上，只是显示白色背景。

有什么错误吗？请告诉我，谢谢。

Adapter
class NeedsAdapter(var context: Context) : RecyclerView.Adapter<NeedsAdapter.ViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): NeedsAdapter.ViewHolder {
        var view = View.inflate(parent.context, R.layout.needs_item, null)
        var parms = ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT)
        view.layoutParams = parms
        return ViewHolder(view)
    }

    override fun getItemCount(): Int {
        return 10;
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
    }


    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

    }

}

片断

class NeedsFragment : Fragment() {

    private lateinit var adapter: NeedsAdapter
    private lateinit var layout: View
    private lateinit var recyclerView: RecyclerView
    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        // Inflate the layout for this fragment
        layout = inflater.inflate(R.layout.fragment_needs, container, false)
        adapter = NeedsAdapter(this!!.activity!!)
        recyclerView = layout.findViewById(R.id.recyclerview)
        recyclerView.addItemDecoration(DividerItemDecoration(context!!, LinearLayoutManager.VERTICAL))
        recyclerView.adapter = adapter
        adapter.notifyDataSetChanged()

        return view
    }

}

我只想显示recyclerview上的项目。

Answer 1

您错过了设置布局管理器

recyclerView.layoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL ,false)