<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context="com.example.admin.demo.MainActivity">

 <AutoCompleteTextView
 android:completionThreshold="2" 
 android:id="@+id/autoCompleteTextView1"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:hint="请输入你要搜索的关键词"
 />
</LinearLayout>

package com.example.admin.demo;

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

public class MainActivity extends AppCompatActivity {
 private AutoCompleteTextView acTextView; 
 //建立一个数组，保存我们想要提示的文本内容
 private String[] res = {"ab1","ab2","ab3"}; @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);

 //初始化控件，返回类型view强制转换成AutoCompleteTextView
 acTextView = (AutoCompleteTextView) findViewById(R.id.autoCompleteTextView1); 

 //添加适配器，并初始化数据源，用来匹配文本框输入的内容
 ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,res);

 //将适配器与当前控件绑定
 acTextView.setAdapter(adapter);
 }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context="com.example.admin.demo.MainActivity">


 <MultiAutoCompleteTextView
 android:completionThreshold="2"
 android:id="@+id/multiAutoCompleteTextView"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:hint="请输入收件人" />
</LinearLayout>

package com.example.admin.demo;

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

public class MainActivity extends AppCompatActivity {
 private MultiAutoCompleteTextView macTextView;
 //建立一个数组，保存我们想要提示的文本内容
 private String[] res = {"ab1","ab2","ab3","cd1","cd2","cd3"};
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);

 //初始化控件，返回类型view强制转换成AutoCompleteTextView
 macTextView = (MultiAutoCompleteTextView) findViewById(R.id.multiAutoCompleteTextView);

 //添加适配器，并初始化数据源，用来匹配文本框输入的内容
 ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,res);

 //将适配器与当前控件绑定
 macTextView.setAdapter(adapter);

 //设置以逗号为分隔符为结束的符号
 macTextView.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());
 }
}