AutoCompleteTextView 自动提示

public class MainActivity extends Activity {
private AutoCompleteTextView autotext;
private ArrayAdapter<String> arrayAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test);

        autotext =(AutoCompleteTextView) findViewById(R.id.autotext);
        String [] arr={"aa","aab","aac"};
        arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,arr);
        autotext.setAdapter(arrayAdapter);
    }

}