多层下拉框

package com.scxh;import java.util.ArrayList;import android.app.Activity;import android.content.Context;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.AdapterView.OnItemSelectedListener;import android.widget.ArrayAdapter;import android.widget.Spinner;import android.widget.TextView;public class MainActivity extends Activity {private ArrayList<String> city;private ArrayList<String> qu;private LayoutInflater inflater;private String[] sheng;private String[] sc_city;private String[] gd_city;private String[] cd_qu;private String[] zy_qu;private MyAdapter1 mMyAdapter1;private MyAdapter2 mMyAdapter2;private MyAdapter3 mMyAdapter3;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);sheng = getResources().getStringArray(R.array.sheng);sc_city = getResources().getStringArray(R.array.sc_city);gd_city = getResources().getStringArray(R.array.gd_city);cd_qu = getResources().getStringArray(R.array.cd_qu);zy_qu = getResources().getStringArray(R.array.zy_qu);city=new ArrayList<String>();qu=new ArrayList<String>();Spinner spinner1 = (Spinner) findViewById(R.id.spinner1);mMyAdapter1 = new MyAdapter1(this, -1);spinner1.setAdapter(mMyAdapter1);spinner1.setOnItemSelectedListener(new MyOnItemSelectedListener1());Spinner spinner2 = (Spinner) findViewById(R.id.spinner2);mMyAdapter2 = new MyAdapter2(this, -1);spinner2.setAdapter(mMyAdapter2);spinner2.setOnItemSelectedListener(new MyOnItemSelectedListener2());Spinner spinner3 = (Spinner) findViewById(R.id.spinner3);mMyAdapter3 = new MyAdapter3(this, -1);spinner3.setAdapter(mMyAdapter3);}class MyAdapter1 extends ArrayAdapter<String> {public MyAdapter1(Context context, int resource) {super(context, resource);inflater = LayoutInflater.from(context);}@Overridepublic int getCount() {return sheng.length;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {if (convertView == null) {convertView = inflater.inflate(R.layout.buju, null);}TextView textview = (TextView) convertView.findViewById(R.id.textview);textview.setText(sheng[position]);return convertView;}@Overridepublic View getDropDownView(int position, View convertView, ViewGroup parent) {if (convertView == null) {convertView = inflater.inflate(R.layout.buju, null);}TextView textview = (TextView) convertView.findViewById(R.id.textview);textview.setText(sheng[position]);return convertView;}}class MyAdapter2 extends ArrayAdapter<String> {public MyAdapter2(Context context, int resource) {super(context, resource);inflater = LayoutInflater.from(context);}@Overridepublic int getCount() {return city.size();}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {if (convertView == null) {convertView = inflater.inflate(R.layout.buju, null);}TextView textview = (TextView) convertView.findViewById(R.id.textview);textview.setText(city.get(position));return convertView;}@Overridepublic View getDropDownView(int position, View convertView, ViewGroup parent) {if (convertView == null) {convertView = inflater.inflate(R.layout.buju, null);}TextView textview = (TextView) convertView.findViewById(R.id.textview);textview.setText(city.get(position));return convertView;}}class MyAdapter3 extends ArrayAdapter<String> {public MyAdapter3(Context context, int resource) {super(context, resource);inflater = LayoutInflater.from(context);}@Overridepublic int getCount() {return qu.size();}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {if (convertView == null) {convertView = inflater.inflate(R.layout.buju, null);}TextView textview = (TextView) convertView.findViewById(R.id.textview);textview.setText(qu.get(position));return convertView;}@Overridepublic View getDropDownView(int position, View convertView, ViewGroup parent) {if (convertView == null) {convertView = inflater.inflate(R.layout.buju, null);}TextView textview = (TextView) convertView.findViewById(R.id.textview);textview.setText(qu.get(position));return convertView;}}class MyOnItemSelectedListener1 implements OnItemSelectedListener {@Overridepublic void onItemSelected(AdapterView<?> parent, View view, int position, long id) {switch (position) {case 0:city.clear();for (String i : sc_city) {city.add(i);}mMyAdapter2.notifyDataSetChanged();break;case 1:city.clear();for (String i : gd_city) {city.add(i);}mMyAdapter2.notifyDataSetChanged();break;default:break;}}@Overridepublic void onNothingSelected(AdapterView<?> parent) {}}class MyOnItemSelectedListener2 implements OnItemSelectedListener {@Overridepublic void onItemSelected(AdapterView<?> parent, View view, int position, long id) {switch (position) {case 0:qu.clear();for (String i : cd_qu) {qu.add(i);}mMyAdapter3.notifyDataSetChanged();break;case 1:qu.clear();for (String i : zy_qu) {qu.add(i);}mMyAdapter3.notifyDataSetChanged();break;default:break;}}@Overridepublic void onNothingSelected(AdapterView<?> parent) {}}}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/LinearLayout1"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="horizontal"    tools:context="com.scxh.MainActivity" >        <Spinner android:id="@+id/spinner1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_weight="1"        />        <Spinner android:id="@+id/spinner2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_weight="1"        />        <Spinner android:id="@+id/spinner3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_weight="1"        /></LinearLayout>

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

<?xml version="1.0" encoding="utf-8"?><resources>    <string-array name="sheng">        <item >四川</item>        <item >广东</item>        <item >青海</item>        <item >陕西</item>    </string-array>        <string-array name="sc_city">        <item >成都</item>        <item >资阳</item>        <item >绵阳</item>        <item >广元</item>        <item >简阳</item>    </string-array>        <string-array name="gd_city">        <item >广州</item>        <item >深圳</item>        <item >中山</item>        <item >东莞</item>    </string-array>        <string-array name="cd_qu">        <item >金牛</item>        <item >成华</item>        <item >高薪</item>        <item >青羊</item>        <item >武侯</item>        <item >锦江</item>    </string-array>         <string-array name="zy_qu">        <item >安岳</item>        <item >乐至</item>        <item >1</item>        <item >2</item>        <item >3</item>    </string-array></resources>