Android AutoCompleteTextView用法

package com.turboradio.googlesdk;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;

public class Ex_4_13 extends Activity {
private static final String [] autoStr = {
    "a","abc","abcd","acd"
};
private AutoCompleteTextView autoText;
    @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        setContentView(R.layout.ex_4_13);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_dropdown_item_1line,autoStr);
        autoText = (AutoCompleteTextView)findViewById(R.id.auto);
        autoText.setAdapter(adapter);
    }

}

ex_4_13.xml

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