需要帮助以在工具栏中进行自动完成的textview

我尝试在工具栏内创建一个自动完成的textview，但是当我从列表中加载数据时它不成功。我的代码： CountryAdapter

class CountryAdapter(
context: Context,resource: Int,textViewResourceId: Int,var items: List<CountryItem>) : ArrayAdapter<CountryItem>(context,resource,textViewResourceId,items) {
internal var tempItems: List<CountryItem> = ArrayList(items)
internal var suggestions: MutableList<CountryItem> = ArrayList()

/**
 * Custom Filter implementation for custom suggestions we provide.
 */
private var nameFilter: Filter = object : Filter() {
    override fun convertResultToString(resultvalue: Any): CharSequence {
        return (resultvalue as CountryItem).countryName
    }

    override fun performFiltering(constraint: CharSequence?): FilterResults {
        return if (constraint != null) {
            suggestions.clear()
            for (people in tempItems) {
                if (people.countryName.toLowerCase().contains(constraint.toString().toLowerCase())) {
                    suggestions.add(people)
                }
            }
            val filterResults = FilterResults()
            filterResults.values = suggestions
            filterResults.count = suggestions.size
            filterResults
        } else {
            FilterResults()
        }
    }

    override fun publishResults(constraint: CharSequence,results: FilterResults?) {
        val filterList = results!!.values as ArrayList<CountryItem>
        if (results.count > 0) {
            clear()
            for (people in filterList) {
                add(people)
                notifyDataSetChanged()
            }
        }
    }
}

init {
    // this makes the difference.
}

override fun getView(position: Int,convertView: View?,parent: ViewGroup): View {
    var view = convertView
    if (convertView == null) {
        val inflater = context.getSystemService(Context.LAYOUT_INflaTER_SERVICE) as LayoutInflater
        view = inflater.inflate(R.layout.country_autocomplete_row,parent,false)
    }
    val people = items[position]
    val lblName = view!!.findViewById(R.id.text_view_name) as TextView
    val img = view.findViewById(R.id.image_view_flag) as ImageView
    lblName.text = people.countryName
    img.setImageResource(people.flagImage)
    return view
}

override fun getFilter(): Filter {
    return nameFilter
}

}

主要活动

class Mainactivity : AppCompatactivity(),NavigationView.OnNavigationItemSelectedListener {
var countryList : List<CountryItem>?= null

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
    setSupportactionBar(toolbar)

    fab.setOnClicklistener { view ->
        snackbar.make(view,"Replace with your own action",snackbar.LENGTH_LONG)
            .setaction("action",null).show()
    }

    val toggle = actionbardrawertoggle(
        this,drawer_layout,toolbar,R.string.navigation_drawer_open,R.string.navigation_drawer_close
    )
    drawer_layout.addDrawerListener(toggle)
    toggle.syncState()

    fillCountryList()

    nav_view.setNavigationItemSelectedListener(this)
}

override fun onBackpressed() {
    if (drawer_layout.isDrawerOpen(GravityCompat.START)) {
        drawer_layout.closeDrawer(GravityCompat.START)
    } else {
        super.onBackpressed()
    }
}

private fun fillCountryList() {
    countryList = mutableListOf(
        CountryItem(1,"Afghanistan",R.drawable.afghanistan),CountryItem(2,"Bangladesh",R.drawable.bangladesh),CountryItem(3,"China",R.drawable.china),CountryItem(4,"India",R.drawable.india),CountryItem(5,"Japan",R.drawable.japan),CountryItem(6,"Nepal",R.drawable.nepal),CountryItem(7,"North Korea",R.drawable.nkorea),CountryItem(8,"South Korea",R.drawable.skorea),CountryItem(9,"Srilanka",R.drawable.srilanka),CountryItem(10,"Pakistan",R.drawable.pakistan)
    )
}

override fun onCreateOptionsMenu(menu: Menu): Boolean {
    // Inflate the menu; this adds items to the action bar if it is present.
    menuInflater.inflate(R.menu.main,menu)

    // Get the search menu.
    val searchMenu = menu.findItem(R.id.app_bar_menu_search)

    // Get SearchView object.
    val searchView = MenuItemCompat.getactionView(searchMenu) as SearchView

    // Get SearchView autocomplete object.
    val searchAutoComplete =
        searchView.findViewById(android.support.v7.appcompat.R.id.search_src_text) as SearchView.SearchAutoComplete
    searchAutoComplete.setBackgroundColor(Color.BLUE)
    searchAutoComplete.setTextColor(Color.GREEN)
    searchAutoComplete.setDropDownBackgroundResource(android.R.color.holo_blue_light)

    // Create a new ArrayAdapter and add data to search auto complete object.
    val dataArr = arrayOf("Afghanistan","Pakistan")

// val newsAdapter = ArrayAdapter（this，android.R.layout.simple_dropdown_item_1line，dataArr） val newsAdapter = CountryAdapter（this，R.layout.activity_main，R.id.text_view_name，countryList !!） searchAutoComplete.setadapter（newsAdapter）

    // Listen to search view item on click event.
    searchAutoComplete.onItemClicklistener =
        AdapterView.OnItemClicklistener { adapterView,view,itemIndex,id ->
            val queryString = adapterView.getItemAtPosition(itemIndex) as String
            searchAutoComplete.setText("" + queryString)
            Toast.makeText(this@Mainactivity,"you clicked $queryString",Toast.LENGTH_LONG).show()
        }

    // Below event is triggered when submit search query.
    searchView.setOnQueryTextListener(object : SearchView.OnQueryTextListener {
        override fun onQueryTextSubmit(query: String): Boolean {
            val alertDialog = AlertDialog.Builder(this@Mainactivity).create()
            alertDialog.setMessage("Search keyword is $query")
            alertDialog.show()
            return false
        }

        override fun onQueryTextChange(newText: String): Boolean {
            if (newText.isnotEmpty()){
                return true
            }

            return false
        }
    })

    return true
}

override fun onOptionsItemSelected(item: MenuItem): Boolean {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button,so long
    // as you specify a parent activity in AndroidManifest.xml.
    when (item.itemId) {
        R.id.action_settings -> return true
        R.id.app_bar_menu_search -> return true
        else -> return super.onOptionsItemSelected(item)
    }
}

override fun onNavigationItemSelected(item: MenuItem): Boolean {
    // Handle navigation view item clicks here.
    when (item.itemId) {
        R.id.nav_camera -> {
            // Handle the camera action
        }
        R.id.nav_gallery -> {

        }
        R.id.nav_slideshow -> {

        }
        R.id.nav_manage -> {

        }
        R.id.nav_share -> {

        }
        R.id.nav_send -> {

        }
    }

    drawer_layout.closeDrawer(GravityCompat.START)
    return true
}

}

如果我使用数组字符串可以，但是当我使用列表时会给我错误

E / Android运行时：致命异常：主要流程：com.robusta.autocompletesearchview，PID：16164 java.lang.IllegalArgumentException：指定为非null的参数为null：方法kotlin.jvm.internal.Intrinsics.checkParameterIsnotNull，参数约束在com.robusta.autocompletesearchview.CountryAdapter $ nameFilter $ 1.publishResults（未知来源：24）在android.widget.Filter $ ResultsHandler.handleMessage（Filter.java:282）在android.os.Handler.dispatchMessage（Handler.java:106）在android.os.Looper.loop（Looper.java:193）在android.app.activityThread.main（activityThread.java:6669）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.RuntimeInit $ MethodAndArgsCaller.run（RuntimeInit.java:493）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:858）

需要帮助以在工具栏中进行自动完成的textview

lipanhaoran 回答：需要帮助以在工具栏中进行自动完成的textview

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