Kotlin/AndroidStudio - 将 listView 与 RecyclerView 连接的问题

Question

我还在学习，我看到我的路还很长。 但是我被我的应用程序卡住了，我在网上找不到任何线索，所以我需要你的帮助。

我在将 listView 与 RecyclerView 连接时遇到问题：在第一个 ACTIVITY 中，我有一个列表，在选择第一个位置后，我的意图是它应该返回一个带有回收器视图（和 cardView）的片段。 不幸的是，我尝试了很多方法，但我仍然不知道解决方案。 有人帮我吗？ 😊

动物栖息地

class AnimalHabitats : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_animal_habitats)

    val itemClickListener =
        OnItemClickListener { listView, v, position, id ->
            if (position == 0) {
                val intent = Intent(
                    this@AnimalHabitats,
                    SavannaFragment::class.java
                )
                startActivity(intent)
            }
        }
    val listView = findViewById<View>(R.id.listAnimal) as ListView
    listView.onItemClickListener = itemClickListener
}}

带有 CardView、RecyclerView 的片段

class SavannaFragment : Fragment() {

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

    val savannaRecyclerView =
        inflater.inflate(R.layout.fragment_savanna, container, false) as RecyclerView

    val savannaAnimalsName = arrayOfNulls<String>(Savanna.savannaArray.size)
    for (i in savannaAnimalsName.indices) {
        savannaAnimalsName[i] = Savanna.savannaArray[i].name
    }
    val savannaAnimalsImage = IntArray(Savanna.savannaArray.size)
    for (i in savannaAnimalsImage.indices) {
        savannaAnimalsImage[i] = Savanna.savannaArray[i].imageResourcesId
    }

    val adapter = RecyclerViewAdapter(savannaAnimalsName, savannaAnimalsImage)
    savannaRecyclerView.adapter = adapter
    val layoutManager = GridLayoutManager(activity, 2)
    savannaRecyclerView.layoutManager = layoutManager
    adapter.setListener(object : RecyclerViewAdapter.Listener {
        override fun onClick(position: Int) {
            val intent = Intent(activity, SavannaDetailActivity::class.java)
            intent.putExtra(SavannaDetailActivity.EXTRA_ANIMAL_ID, position)
            activity!!.startActivity(intent)
        }
    })
    return savannaRecyclerView
}}

回收器视图适配器

internal class RecyclerViewAdapter(
private val title: Array<String?>,
private val imageIds: IntArray) : RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder>(){
private var listener: Listener? = null
internal interface Listener {
    fun onClick(position: Int)
}
class ViewHolder(internal val cardView: CardView) : RecyclerView.ViewHolder(
    cardView
)
override fun getItemCount(): Int {
    return title.size
}
fun setListener(listener: Listener?) {
    this.listener = listener
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
    val cv: CardView = LayoutInflater.from(parent.context)
        .inflate(R.layout.card_view_animal, parent, false) as CardView
    return ViewHolder(cv)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
    val cardView: CardView = holder.cardView
    val imageView: ImageView = cardView.findViewById(R.id.info_image) as ImageView
    val drawable = ContextCompat.getDrawable(cardView.context, imageIds[position])
    imageView.setImageDrawable(drawable)
    imageView.contentDescription = title[position]
    val textView = cardView.findViewById(R.id.info_text) as TextView
    textView.text = title[position]
    cardView.setOnClickListener {
        if (listener != null) {
            listener!!.onClick(position)
        }
    }
}

}

Answer 1

然后在您的活动中执行此操作以添加片段：

 val itemClickListener =
        OnItemClickListener { listView, v, position, id ->
            if (position == 0) {
                FragmentManager manager = getFragmentManager();
                FragmentTransaction transaction = manager.beginTransaction();
                transaction.add(R.id.container,YOUR_FRAGMENT_NAME,YOUR_FRAGMENT_STRING_TAG);
                transaction.addToBackStack(null);
                transaction.commit();
            }
        }

//查看id 你想在哪里显示你的fragment

R.id.container

//片段的实例

YOUR_FRAGMENT_NAME

//任何字符串值，以区分片段与其他片段

YOUR_FRAGMENT_STRING_TAG