android:id="@+id/multiAutoCompleteTextView1"
       
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/autoCompleteTextView1"
        android:completionThreshold="3"
        android:hint="@string/N_name" />

/*

*下面是activit。main的

*/

public class MainActivity extends Activity {
 private AutoCompleteTextView ACTextView;
 private MultiAutoCompleteTextView MACTextView;//多个选择
 private String[] res={"baicheng","bixin","beijing","beifang","guangzhou"};//数据源
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  ACTextView=(AutoCompleteTextView) findViewById(R.id.autoCompleteTextView1);
  ArrayAdapter<String> adapeter=new ArrayAdapter<String>(this,
    android.R.layout.simple_expandable_list_item_1, res);
  //adapter为适配器，至于为什么要做一个适配器，用来初始化数据源。
  ACTextView.setAdapter(adapeter);//ACTextView与数据源相连。
  MACTextView=(MultiAutoCompleteTextView) findViewById(R.id.multiAutoCompleteTextView1);
  MACTextView.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());
 }