Android使用android-wheel实现省市县三级联动

{"citylist":
 [{"p":"河北",
  "c":[{"n":"石家庄",
  "a":[{"s":"长安区"},{"s":"桥东区"}，{"s":"鹿泉市"}]
 }]
}

<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="#000000"
  android:orientation="vertical" >

  <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_margin="10dp"
    android:text="请选择城市"
    android:textColor="#ffffff"
    android:textSize="20sp" />

  <LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/layout_bg"
    android:orientation="horizontal" >

    <kankan.wheel.widget.WheelView
      android:id="@+id/id_province"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="1" >
    </kankan.wheel.widget.WheelView>

    <kankan.wheel.widget.WheelView
      android:id="@+id/id_city"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="1" >
    </kankan.wheel.widget.WheelView>

    <kankan.wheel.widget.WheelView
      android:id="@+id/id_area"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="1" >
    </kankan.wheel.widget.WheelView>
  </LinearLayout>
  
  <Button 
 android:onClick="showChoose"
 android:layout_gravity="right"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="确定"
    />
  

</LinearLayout>

package com.example.wheel_province;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;

import kankan.wheel.widget.OnWheelChangedListener;
import kankan.wheel.widget.WheelView;
import kankan.wheel.widget.adapters.ArrayWheelAdapter;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

/**
 * 
 * @author zhy
 * 
 */
public class CitiesActivity extends Activity implements OnWheelChangedListener
{
 /**
 * 把全国的省市区的信息以json的格式保存，解析完成后赋值为null
 */
 private JSONObject mJsonObj;
 /**
 * 省的WheelView控件
 */
 private WheelView mProvince;
 /**
 * 市的WheelView控件
 */
 private WheelView mCity;
 /**
 * 区的WheelView控件
 */
 private WheelView mArea;

 /**
 * 所有省
 */
 private String[] mProvinceDatas;
 /**
 * key - 省 value - 市s
 */
 private Map<String, String[]> mCitisDatasMap = new HashMap<String, String[]>();
 /**
 * key - 市 values - 区s
 */
 private Map<String, String[]> mAreaDatasMap = new HashMap<String, String[]>();

 /**
 * 当前省的名称
 */
 private String mCurrentProviceName;
 /**
 * 当前市的名称
 */
 private String mCurrentCityName;
 /**
 * 当前区的名称
 */
 private String mCurrentAreaName ="";

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

 initJsonData();

 mProvince = (WheelView) findViewById(R.id.id_province);
 mCity = (WheelView) findViewById(R.id.id_city);
 mArea = (WheelView) findViewById(R.id.id_area);

 initDatas();

 mProvince.setViewAdapter(new ArrayWheelAdapter<String>(this, mProvinceDatas));
 // 添加change事件
 mProvince.addChangingListener(this);
 // 添加change事件
 mCity.addChangingListener(this);
 // 添加change事件
 mArea.addChangingListener(this);

 mProvince.setVisibleItems(5);
 mCity.setVisibleItems(5);
 mArea.setVisibleItems(5);
 updateCities();
 updateAreas();

 }

 /**
 * 根据当前的市，更新区WheelView的信息
 */
 private void updateAreas()
 {
 int pCurrent = mCity.getCurrentItem();
 mCurrentCityName = mCitisDatasMap.get(mCurrentProviceName)[pCurrent];
 String[] areas = mAreaDatasMap.get(mCurrentCityName);

 if (areas == null)
 {
  areas = new String[] { "" };
 }
 mArea.setViewAdapter(new ArrayWheelAdapter<String>(this, areas));
 mArea.setCurrentItem(0);
 }

 /**
 * 根据当前的省，更新市WheelView的信息
 */
 private void updateCities()
 {
 int pCurrent = mProvince.getCurrentItem();
 mCurrentProviceName = mProvinceDatas[pCurrent];
 String[] cities = mCitisDatasMap.get(mCurrentProviceName);
 if (cities == null)
 {
  cities = new String[] { "" };
 }
 mCity.setViewAdapter(new ArrayWheelAdapter<String>(this, cities));
 mCity.setCurrentItem(0);
 updateAreas();
 }

 /**
 * 解析整个Json对象，完成后释放Json对象的内存
 */
 private void initDatas()
 {
 try
 {
  JSONArray jsonArray = mJsonObj.getJSONArray("citylist");
  mProvinceDatas = new String[jsonArray.length()];
  for (int i = 0; i < jsonArray.length(); i++)
  {
  JSONObject jsonP = jsonArray.getJSONObject(i);// 每个省的json对象
  String province = jsonP.getString("p");// 省名字

  mProvinceDatas[i] = province;

  JSONArray jsonCs = null;
  try
  {
   /**
   * Throws JSONException if the mapping doesn't exist or is
   * not a JSONArray.
   */
   jsonCs = jsonP.getJSONArray("c");
  } catch (Exception e1)
  {
   continue;
  }
  String[] mCitiesDatas = new String[jsonCs.length()];
  for (int j = 0; j < jsonCs.length(); j++)
  {
   JSONObject jsonCity = jsonCs.getJSONObject(j);
   String city = jsonCity.getString("n");// 市名字
   mCitiesDatas[j] = city;
   JSONArray jsonAreas = null;
   try
   {
   /**
    * Throws JSONException if the mapping doesn't exist or
    * is not a JSONArray.
    */
   jsonAreas = jsonCity.getJSONArray("a");
   } catch (Exception e)
   {
   continue;
   }

   String[] mAreasDatas = new String[jsonAreas.length()];// 当前市的所有区
   for (int k = 0; k < jsonAreas.length(); k++)
   {
   String area = jsonAreas.getJSONObject(k).getString("s");// 区域的名称
   mAreasDatas[k] = area;
   }
   mAreaDatasMap.put(city, mAreasDatas);
  }

  mCitisDatasMap.put(province, mCitiesDatas);
  }

 } catch (JSONException e)
 {
  e.printStackTrace();
 }
 mJsonObj = null;
 }

 /**
 * 从assert文件夹中读取省市区的json文件，然后转化为json对象
 */
 private void initJsonData()
 {
 try
 {
  StringBuffer sb = new StringBuffer();
  InputStream is = getAssets().open("city.json");
  int len = -1;
  byte[] buf = new byte[1024];
  while ((len = is.read(buf)) != -1)
  {
  sb.append(new String(buf, 0, len, "gbk"));
  }
  is.close();
  mJsonObj = new JSONObject(sb.toString());
 } catch (IOException e)
 {
  e.printStackTrace();
 } catch (JSONException e)
 {
  e.printStackTrace();
 }
 }

 /**
 * change事件的处理
 */
 @Override
 public void onChanged(WheelView wheel, int oldValue, int newValue)
 {
 if (wheel == mProvince)
 {
  updateCities();
 } else if (wheel == mCity)
 {
  updateAreas();
 } else if (wheel == mArea)
 {
  mCurrentAreaName = mAreaDatasMap.get(mCurrentCityName)[newValue];
 }
 }

 public void showChoose(View view)
 {
 Toast.makeText(this, mCurrentProviceName + mCurrentCityName + mCurrentAreaName, 1).show();
 }
}