xml - 片段错误Kotlin中的ListView

Question

KT的新手。我在执行列表 View 时遇到一些错误。不确定为什么我会遇到这些问题。是因为它扩展了片段吗？有人可以指出我正确的方向吗？

import android.os.Bundle
import android.support.v4.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ListView
import android.widget.ArrayAdapter

class Chatroom : Fragment() {

    private lateinit var listView ListView

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {

        var listView = findViewById(R.id.chatroom_list_view) as ListView

        val testList = "hu, tu, su, send, pe, t"

        val adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, testList)
        listView.adapter = adapter


        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.chatroom, container, false)
    }

失误

Picture of Errors

.xml

<ListView
            android:id="@+id/chatroom_list_view"
            android:layout_width="368dp"
            android:layout_height="436dp"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            app:layout_constraintBottom_toTopOf="@+id/messageTextField"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/search" />

Answer 1

像这样更改您的代码。

class Chatroom : Fragment() {

private lateinit var listView: ListView

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                          savedInstanceState: Bundle?): View? {
    val rootView = inflater.inflate(R.layout.chatroom, container, false)

    listView = rootView.findViewById(R.id.chatroom_list_view)

    val testList = arrayOf("hu", "tu", "su", "send", "pe", "t")

    val adapter = ArrayAdapter(context, android.R.layout.simple_list_item_1, testList)
    listView.adapter = adapter


    return rootView
}