今天没事跟群里面侃大山，有个哥们说道Android Wheel这个控件，以为是Andriod内置的控件，google一把，发现是个github上的一个控件。
下载地址：https://code.google.com/p/android-wheel/ 发现很适合做省市县三级联动就做了一个。
先看下效果图：
1、首先导入github上的wheel项目
2、新建个项目，然后选择记得右键->Properties->Android中将wheel添加为lib：
上面两个步骤是导入所有开源项目的过程了。
3、下面开始代码的编写：首先是省市区的json文件，放置在asserts的city.json中：
大概的格式先了解一下，一会代码会根据这样的格式解析
{"citylist":
[{"p":"河北",
"c":[{"n":"石家庄",
"a":[{"s":"长安区"},{"s":"桥东区"}，{"s":"鹿泉市"}]
}]
}4、布局文件，比较简单就3个WheelView分别代表省，市，县，还有一个按钮：
<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>
5、Activity的编写：注释相当详细，节不赘述了。
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;
public class CitiesActivity extends Activity implements OnWheelChangedListener
{
private JSONObject mJsonObj;
private WheelView mProvince;
private WheelView mCity;
private WheelView mArea;
private String[] mProvinceDatas;
private Map<String, String[]> mCitisDatasMap = new HashMap<String, String[]>();
private Map<String, String[]> mAreaDatasMap = new HashMap<String, String[]>();
private String mCurrentProviceName;
private String mCurrentCityName;
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();
}
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);
}
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();
}
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
{
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
{
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;
}
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();
}
}
@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();
}
}
源码下载：http://xiazai.jb51.net/201608/yuanma/Androidwheel(jb51.net).rar
