Kotlin 初学者求助：如何修复 RecyclerView 和 SearchView 的搜索过滤问题？🔍

嘿，大家好！👋

我最近在搞我的第一个 Android 应用，结果被 RecyclerView 和 SearchView 搞得有点崩溃。😅 我已经能成功加载手机联系人到 RecyclerView 里了，但搜索功能就是不太对劲。看了好多视频教程，还是没搞定。有没有大佬能帮我看看这段代码到底哪里出问题了？🙏

这是我的 MainActivity 代码：

class MainActivity : AppCompatActivity(), EasyPermissions.PermissionCallbacks {

    // SearchView 和 RecyclerView
    private lateinit var recyclerView: RecyclerView
    private lateinit var searchView: SearchView
    private var mList = ArrayList<ContactModel>()
    private lateinit var adapter: RCVAdapter

    private lateinit var binding: ActivityMainBinding
    var arrayList: ArrayList<ContactModel> = arrayListOf()
    var rcvAdapter: RCVAdapter = RCVAdapter(arrayList)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        val view = binding.root
        setContentView(view)

        // 初始化 RecyclerView 和 SearchView
        recyclerView = findViewById(R.id.rcvContact)
        searchView = findViewById(R.id.TxtSearch)
        recyclerView.setHasFixedSize(true)
        recyclerView.layoutManager = LinearLayoutManager(this)

        // 设置适配器
        adapter = RCVAdapter(arrayList)
        recyclerView.adapter = adapter

        if (checkContactPermissions()) {
            binding.apply {
                rcvContact.apply {
                    layoutManager = LinearLayoutManager(this@MainActivity)
                    adapter = RCVAdapter(arrayList)
                }
            }
            // 加载联系人
            getContacts()
        }

        // 设置搜索监听器
        searchView.setOnQueryTextListener(object : SearchView.OnQueryTextListener {
            override fun onQueryTextSubmit(query: String?): Boolean {
                return false
            }

            override fun onQueryTextChange(newText: String?): Boolean {
                filterList(newText)
                return true
            }
        })
    }

    // 搜索过滤
    private fun filterList(query: String?) {
        if (query != null) {
            val filteredList = arrayList // 这里应该是个新列表
            for (i in mList) {
                if (i.contname.lowercase(Locale.ROOT).contains(query)) {
                    filteredList.add(i)
                }
            }
            if (filteredList.isEmpty()) {
                Toast.makeText(this, "No Contact found!", Toast.LENGTH_SHORT).show()
            } else {
                adapter.setFilteredList(filteredList) // 这里应该传 filteredList
            }
        }
    }

    private fun getContacts() {
        // 加载联系人逻辑
    }
}

这是我的 RCVAdapter 代码：

class RCVAdapter(var contactList: ArrayList<ContactModel>) : RecyclerView.Adapter<RCVAdapter.MyViewHolder>() {

    inner class MyViewHolder(val binding: ItemContactBinding) : RecyclerView.ViewHolder(binding.root) {
        val contid = binding.TxtContID
        val contname = binding.TxtContName
        val contno = binding.TxtContNo
        val contphoto = binding.ImgContPhoto
        val contemail = binding.TxtContEmail
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
        return MyViewHolder(
            ItemContactBinding.inflate(
                LayoutInflater.from(parent.context),
                parent,
                false
            )
        )
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        val item = contactList[position]
        holder.binding.TxtContID.text = item.contid.toString()
        holder.binding.TxtContName.text = item.contname
        holder.binding.TxtContNo.text = item.contnumber

        if (contactList[position].contPhoto != null)
            holder.binding.ImgContPhoto.setImageBitmap(contactList[position].contPhoto)
        else
            holder.binding.ImgContPhoto.setImageDrawable(ContextCompat.getDrawable(holder.itemView.context, R.drawable.ic_people_24))

        holder.binding.TxtContEmail.text = item.contemail
    }

    override fun getItemCount(): Int = contactList.size

    fun setFilteredList(contactList: List<ContactModel>) {
        this.contactList = contactList as ArrayList<ContactModel>
        notifyDataSetChanged()
    }
}

还有我的 ContactModel 类：

data class ContactModel(
    var contid: String = "",
    var contname: String = "",
    var contnumber: String = "",
    var contPhoto: Bitmap? = null,
    var contemail: String = "",
)

我觉得问题可能出在 filterList 方法里，特别是 filteredList 的使用上。🤔 我试着用一个新的 ArrayList 来存储过滤后的结果，但好像没什么用。有没有人能帮我指出问题所在？谢谢！🙏

PS: 我是从 VB.NET 转过来的，对 Kotlin 还在摸索中，求轻喷！😅

标签：Android、Kotlin、RecyclerView、SearchView、初学者问题