Android Kotlin listview适配器筛选器仅显示第一项

class CustomAdapter(private val context: Context, private val data: ArrayList<String>) : BaseAdapter() {
    private var filteredData: ArrayList<String> = ArrayList()

    init {
        filteredData.add(data[0]) // 只显示第一项
    }

    override fun getCount(): Int {
        return filteredData.size
    }

    override fun getItem(position: Int): Any {
        return filteredData[position]
    }

    override fun getItemId(position: Int): Long {
        return position.toLong()
    }

    override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View {
        val view: View
        val viewHolder: ViewHolder

        if (convertView == null) {
            view = LayoutInflater.from(context).inflate(R.layout.list_item, parent, false)
            viewHolder = ViewHolder(view)
            view.tag = viewHolder
        } else {
            view = convertView
            viewHolder = view.tag as ViewHolder
        }

        viewHolder.itemTextView.text = filteredData[position]

        return view
    }

    private class ViewHolder(view: View) {
        val itemTextView: TextView = view.findViewById(R.id.itemTextView)
    }
}

val listView: ListView = findViewById(R.id.listView)
val data: ArrayList<String> = ArrayList()
data.add("Item 1")
data.add("Item 2")
data.add("Item 3")

val adapter = CustomAdapter(this, data)
listView.adapter = adapter

val filterText: EditText = findViewById(R.id.filterText)
filterText.addTextChangedListener(object : TextWatcher {
    override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}

    override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
        adapter.filter.filter(s) // 根据输入的文本筛选数据
    }

    override fun afterTextChanged(s: Editable?) {}
})

<ListView
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<EditText
    android:id="@+id/filterText"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="Filter" />