{"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();  
    }  
}