autoComplete TextView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <!-- 定义一个自动完成文本框，
        指定输入一个字符后进行提示 -->
    <AutoCompleteTextView
        android:id="@+id/auto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:completionHint="请选择您喜欢的图书："
        android:dropDownHorizontalOffset="10dp"
        android:completionThreshold="1"/>
    <!-- 定义一个MultiAutoCompleteTextView组件 -->
    <MultiAutoCompleteTextView
        android:id="@+id/mauto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:completionThreshold="1"/>
</LinearLayout>

package com.example.autocompletetextview

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.ArrayAdapter
import android.widget.AutoCompleteTextView
import android.widget.MultiAutoCompleteTextView

class MainActivity : AppCompatActivity() {

    // 定义字符串数组，作为提示的文本
    private var books = arrayOf("aaaa", "abbbbbbb",
        "abcccccccccc", "ccccccccc")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        // 创建一个ArrayAdapter，封装数组
        val aa = ArrayAdapter(this, android.R.layout.simple_dropdown_item_1line, books)
        val actv = findViewById<AutoCompleteTextView>(R.id.auto)
        // 设置Adapter
        actv.setAdapter(aa)
        val mauto = findViewById<MultiAutoCompleteTextView>(R.id.mauto)
        // 设置Adapter
        mauto.setAdapter(aa)
        // 为MultiAutoCompleteTextView设置分隔符
        mauto.setTokenizer(MultiAutoCompleteTextView.CommaTokenizer())
    }
}