<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent">
 <AutoCompleteTextView
  android:id="@+id/myAutoCompleteTextView"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content" />
</LinearLayout>

package com.example.sample_5_1;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
public class AutoCompleteActivity extends AppCompatActivity {
 private static final String[] myStr = new String[]{
   "vae","victory","vision","virtue","vital"
 };
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_auto_complete);
  ArrayAdapter<String> aa = new ArrayAdapter<String>( //创建适配器
    this,           // Context
    android.R.layout.simple_dropdown_item_1line,
    //使用Android自带的简单布局
    myStr);          //资源数组
  AutoCompleteTextView myAutoCompleteTextView =
    (AutoCompleteTextView) findViewById(R.id.myAutoCompleteTextView);
     //得到控件的引用
  myAutoCompleteTextView.setAdapter(aa); //设置适配器
  myAutoCompleteTextView.setThreshold(1); //定义需要用户输入的字符数
 }
}