Kotlin中RecyclerView动态添加数据失效及点击无响应问题求助

通过EditText输入文本，点击按钮向RecyclerView动态添加文本项，点击按钮将文本加入Adapter关联的Array并调用adapter.notifyDataSetChanged()后，RecyclerView既不更新，也无法检测点击事件。但修改Array中已有文本的值（不改变数组长度）时，RecyclerView能正常显示变化。

相关代码 #

MainActivity.kt #

package com.example.recycleviewwork

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.view.View.OnClickListener
import android.widget.Button
import android.widget.EditText
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView

class Travel : AppCompatActivity(), View.OnClickListener {
    var check_travel_list = arrayOf<String>("cni", "psp", "hhn", "ddp", "ppe", "leh")
    var state_check_bool = arrayOf<Boolean>(false, false, false, false,false,false)
    val adapter = travel_list_adapter(check_travel_list,state_check_bool, this)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_travel)
        var textEditValue = ""
        // RECYCLEVIEW Travel page
        val recview_travel = findViewById<RecyclerView>(R.id.travel_recview)
        recview_travel.layoutManager = LinearLayoutManager(this)
         recview_travel.adapter = adapter

        //EDIT text
        val edit_text_view = findViewById<EditText>(R.id.textedit)

        // ADD travel button
        val button_add_travel = findViewById<Button>(R.id.button_travel)
        button_add_travel.setOnClickListener()
        {
            textEditValue = edit_text_view.text.toString()
            check_travel_list += textEditValue
            state_check_bool += false
            adapter.notifyDataSetChanged()
            println(textEditValue)

        }

        }




    override fun onClick(vue: View) {
        val index = vue.tag as Int
        //changement des bool de couleur
        if(index != null)
        {
            state_check_bool[index] =  !state_check_bool[index]
            adapter.notifyDataSetChanged()
        }


    }
}

Adapter.kt #

package com.example.recycleviewwork

import android.graphics.Color
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.cardview.widget.CardView
import androidx.recyclerview.widget.RecyclerView

 class travel_list_adapter(val travel_check_list : Array <String>,val travel_state_check : Array<Boolean> , val travel_click : View.OnClickListener) : RecyclerView.Adapter<travel_list_adapter.ViewHolder>()
{
    class ViewHolder (itemview: View ): RecyclerView.ViewHolder(itemview)
    {
       val cartview = itemview.findViewById<CardView>(R.id.cartview_travel_list)
        val text_check = itemview.findViewById<TextView>(R.id.text_travel_list)
    }
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): travel_list_adapter.ViewHolder {
        val inflater = LayoutInflater.from(parent.context)
        val view_item = inflater.inflate(R.layout.travel_list,parent,false)
        return ViewHolder(view_item)
    }



    override fun getItemCount(): Int {
        return  travel_check_list.size
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val current_check = travel_check_list[position]
        val state_state_check = travel_state_check[position]
        holder.cartview.setOnClickListener(travel_click)
        holder.cartview.tag = position
        holder.text_check.text = current_check
        if(state_state_check == true)
        {
        holder.text_check.setTextColor(Color.parseColor("#8BC34A"))
            }
        else
        {
            holder.text_check.setTextColor(Color.parseColor("#000000"))
        }

    }


}

问题核心在于Kotlin Array的不可变性：

• Array是固定长度集合，使用+=操作符时，并未修改原数组，而是生成了一个新数组对象。但Adapter持有的还是旧数组的引用，调用notifyDataSetChanged()时，读取的依然是旧数组的长度和内容，所以不会更新。
• 修改已有元素时，直接操作的是原数组内的元素，Adapter引用未变，因此能正常刷新。

修复步骤：

1. 将Array替换为可变集合MutableList，支持动态添加元素且不改变引用：

   // 替换原数组定义
   var check_travel_list = mutableListOf<String>("cni", "psp", "hhn", "ddp", "ppe", "leh")
   var state_check_bool = mutableListOf<Boolean>(false, false, false, false,false,false)
   

2. 更新Adapter的参数类型为MutableList：

   class travel_list_adapter(
       val travel_check_list: MutableList<String>,
       val travel_state_check: MutableList<Boolean>,
       val travel_click: View.OnClickListener
   ) : RecyclerView.Adapter<travel_list_adapter.ViewHolder>() {
       
       override fun getItemCount(): Int {
           return travel_check_list.size
       }
       
       // 其他代码保持不变
   }
   

3. 修改添加元素的逻辑，直接向MutableList中添加：

   button_add_travel.setOnClickListener {
       textEditValue = edit_text_view.text.toString()
       check_travel_list.add(textEditValue)
       state_check_bool.add(false)
       adapter.notifyDataSetChanged()
       println(textEditValue)
   }
   

额外优化建议：

• 用notifyItemInserted()替代notifyDataSetChanged()，只刷新新增项，提升性能：

  val newIndex = check_travel_list.size
  check_travel_list.add(textEditValue)
  state_check_bool.add(false)
  adapter.notifyItemInserted(newIndex)
  

• 建议在Adapter内部处理点击事件，避免通过Tag传递索引的潜在问题。

内容的提问来源于stack exchange，提问作者launchcake inc