多层级Spinner列表选项实时更新树形层级(选择城市)

package com.example.spinnerdemo;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;

public class MainActivity extends Activity {

    private Spinner provinceSpinner = null; // 省（省、直辖市）
    private Spinner citySpinner = null; // 市
    private Spinner countrySpinner = null; // 区

    private ArrayAdapter<String> provinceAdapter = null; // 省
    private ArrayAdapter<String> cityAdapter = null; // 市
    private ArrayAdapter<String> countryAdapter = null; // 区

    private int provincePosition = 3;

    // 省级选项值
    private String[] province = new String[] { "北京", "上海", "天津", "广东" };// ,"重庆","黑龙江","江苏","山东","浙江","香港","澳门"};

    // 市级选项值
    private String[][] city = new String[][] {
            { "东城区", "西城区", "崇文区", "宣武区", "朝阳区", "海淀区", "丰台区", "石景山区", "门头沟区","房山区", "通州区", "顺义区", "大兴区", "昌平区", "平谷区", "怀柔区", "密云县","延庆县" },
            { "长宁区", "静安区", "普陀区", "闸北区", "虹口区" },
            { "和平区", "河东区", "河西区", "南开区", "河北区", "红桥区", "塘沽区", "汉沽区", "大港区","东丽区" }, 
            { "广州", "深圳", "韶关" // ,"珠海","汕头","佛山","湛江","肇庆","江门","茂名","惠州","梅州",
            // "汕尾","河源","阳江","清远","东莞","中山","潮州","揭阳","云浮"
            } };

    // 区县级选项值
    private String[][][] country = new String[][][] 
            {
                    {   //北京
                        {"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"},
                        {"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"}
                    },
                    {    //上海
                        {"无"},{"无"},{"无"},{"无"},{"无"}
                    },
                    {    //天津
                        {"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"},{"无"}
                    },
                    {    //广东
                        {"海珠区","荔湾区","越秀区","白云区","萝岗区","天河区","黄埔区","花都区","从化市","增城市","番禺区","南沙区"}, //广州
                        {"宝安区","福田区","龙岗区","罗湖区","南山区","盐田区"}, //深圳
                        {"武江区","浈江区","曲江区","乐昌市","南雄市","始兴县","仁化县","翁源县","新丰县","乳源县"}  //韶关
                    }
            };


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        setContentView(R.layout.activity_main);

        provinceSpinner = (Spinner) findViewById(R.id.spinner_province);
        citySpinner = (Spinner) findViewById(R.id.spinner_city);
        countrySpinner = (Spinner) findViewById(R.id.spinner_country);

        // 装载适配器和值
        provinceAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, province);
        provinceSpinner.setAdapter(provinceAdapter);

        cityAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, city[3]);
        citySpinner.setAdapter(cityAdapter);

        countryAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, country[3][0]);
        countrySpinner.setAdapter(countryAdapter);

        // 省下拉框监听
        provinceSpinner
                .setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

                    @Override
                    public void onItemSelected(AdapterView<?> arg0, View arg1,
                            int position, long arg3) {

                        cityAdapter = new ArrayAdapter<String>(
                                getApplication(),
                                android.R.layout.simple_spinner_item,
                                city[position]);
                        citySpinner.setAdapter(cityAdapter);

                        provincePosition = position; // 记录当前省级序号，留给下面修改县级适配器时用
                    }

                    @Override
                    public void onNothingSelected(AdapterView<?> arg0) {

                    }

                });

        // 市级下拉监听
        citySpinner
                .setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

                    @Override
                    public void onItemSelected(AdapterView<?> arg0, View arg1,
                            int position, long arg3) {
                        countryAdapter = new ArrayAdapter<String>(
                                getApplication(),
                                android.R.layout.simple_spinner_item,
                                country[provincePosition][position]);
                        countrySpinner.setAdapter(countryAdapter);
                    }

                    @Override
                    public void onNothingSelected(AdapterView<?> arg0) {

                    }
                });
    }
}

xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#e0e0e0"
    android:orientation="horizontal" >
    <Spinner
        android:id="@+id/spinner_province"
        android:layout_width="0dip"
        android:layout_weight="1"
        android:layout_height="wrap_content" />

    <Spinner
        android:id="@+id/spinner_city"
        android:layout_width="0dip"
        android:layout_weight="1"
        android:layout_height="wrap_content" />

    <Spinner
        android:id="@+id/spinner_country"
        android:layout_width="0dip"
        android:layout_weight="1"
        android:layout_height="wrap_content" />
</LinearLayout>