Android省市区三级联动选择，转载请注明http://blog.csdn.net/wulianghuan/article/details/41549189

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最近项目要做一个，类似淘宝手机客户端的，选择收货地址的三级联动滚动选择组件，下面是它的大致界面截图：

在iOS中有个叫UIPickerView的选择器，并且在dataSource中定义了UIPickerView的数据源和定制内容，所以用只要熟悉它的基本用法，要实现这么个三级联动滑动选择是挺简单的。 

言归正传，今天讨论的是在Android里面如何来实现这么个效果，那么如何实现呢？？？ 相信部分童鞋首先想到的是android.widget.DatePicker和android.widget.TimePicker，因为它们的样子长得很像，事实就是它们仅仅是长得相而已，Google在设计这个两个widget的时候，并没有提供对外的数据源适配接口，带来的问题就是，我们只能通过它们来选择日期和时间，至于为什么这样设计，如果有童鞋知道，请给我留言，Thanks~

DatePicker.class包含的方法截图：

 全都是关于时间获取用的方法.

好了，既然在Android中没办法偷懒的用一个系统widget搞定，那么只能自己来自定义view来实现了，这篇就围绕这个来展开分享一下，我在项目中实现这个的全过程。首先是做了下开源代码调研，在github上面有一个叫做 android-wheel 的开源控件,  代码地址https://github.com/maarek/android-wheel

是一个非常好用的组件，对于数据适配接口的抽取和事件的回调都做了抽取，代码的耦合度低，唯一不足就是在界面的定制这块，如果你需要做更改，需要去动源代码的。我这里在界面的代码做了改动，放在我的项目src目录下了：

在此次项目中，省市区及邮编的数据是放在了assets/province_data.xml里面，是产品经理花了好几天时间整理的，绝对是最齐全和完善了，辛苦辛苦！！！

关于XML的解析，一共有SAX、PULL、DOM三种解析方式，这里就不讲了，可以看我的前面的几篇学习的文章：

Android解析XML方式(一)使用SAX解析

Android解析XML方式(二)使用PULL解析XML

Android解析XML方式(三)使用DOM解析XML

此次项目中使用的是SAX解析方式，因为它占用内存少，并且速度快，数据解析代码写在了 com.mrwujay.cascade.service/XmlParserHandler.Java中，代码如下：

package com.mrwujay.cascade.service;

import java.util.ArrayList;
import java.util.List;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import com.mrwujay.cascade.model.CityModel;
import com.mrwujay.cascade.model.DistrictModel;
import com.mrwujay.cascade.model.ProvinceModel;

public class XmlParserHandler extends DefaultHandler {

    /**
     * 存储所有的解析对象
     */
    private List provinceList = new ArrayList();

    public XmlParserHandler() {

    }

    public List getDataList() {
        return provinceList;
    }

    @Override
    public void startDocument() throws SAXException {
        // 当读到第一个开始标签的时候，会触发这个方法
    }

    ProvinceModel provinceModel = new ProvinceModel();
    CityModel cityModel = new CityModel();
    DistrictModel districtModel = new DistrictModel();

    @Override
    public void startElement(String uri, String localName, String qName,
            Attributes attributes) throws SAXException {
        // 当遇到开始标记的时候，调用这个方法
        if (qName.equals("province")) {
            provinceModel = new ProvinceModel();
            provinceModel.setName(attributes.getValue(0));
            provinceModel.setCityList(new ArrayList());
        } else if (qName.equals("city")) {
            cityModel = new CityModel();
            cityModel.setName(attributes.getValue(0));
            cityModel.setDistrictList(new ArrayList());
        } else if (qName.equals("district")) {
            districtModel = new DistrictModel();
            districtModel.setName(attributes.getValue(0));
            districtModel.setZipcode(attributes.getValue(1));
        }
    }

    @Override
    public void endElement(String uri, String localName, String qName)
            throws SAXException {
        // 遇到结束标记的时候，会调用这个方法
        if (qName.equals("district")) {
            cityModel.getDistrictList().add(districtModel);
        } else if (qName.equals("city")) {
            provinceModel.getCityList().add(cityModel);
        } else if (qName.equals("province")) {
            provinceList.add(provinceModel);
        }
    }

    @Override
    public void characters(char[] ch, int start, int length)
            throws SAXException {
    }

}

package com.mrwujay.cascade.service;

import java.util.ArrayList;
import java.util.List;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import com.mrwujay.cascade.model.CityModel;
import com.mrwujay.cascade.model.DistrictModel;
import com.mrwujay.cascade.model.ProvinceModel;

public class XmlParserHandler extends DefaultHandler {

	/**
	 * 存储所有的解析对象
	 */
	private List provinceList = new ArrayList();
	 	  
	public XmlParserHandler() {
		
	}

	public List getDataList() {
		return provinceList;
	}

	@Override
	public void startDocument() throws SAXException {
		// 当读到第一个开始标签的时候，会触发这个方法
	}

	ProvinceModel provinceModel = new ProvinceModel();
	CityModel cityModel = new CityModel();
	DistrictModel districtModel = new DistrictModel();
	
	@Override
	public void startElement(String uri, String localName, String qName,
			Attributes attributes) throws SAXException {
		// 当遇到开始标记的时候，调用这个方法
		if (qName.equals("province")) {
			provinceModel = new ProvinceModel();
			provinceModel.setName(attributes.getValue(0));
			provinceModel.setCityList(new ArrayList());
		} else if (qName.equals("city")) {
			cityModel = new CityModel();
			cityModel.setName(attributes.getValue(0));
			cityModel.setDistrictList(new ArrayList());
		} else if (qName.equals("district")) {
			districtModel = new DistrictModel();
			districtModel.setName(attributes.getValue(0));
			districtModel.setZipcode(attributes.getValue(1));
		}
	}

	@Override
	public void endElement(String uri, String localName, String qName)
			throws SAXException {
		// 遇到结束标记的时候，会调用这个方法
		if (qName.equals("district")) {
			cityModel.getDistrictList().add(districtModel);
        } else if (qName.equals("city")) {
        	provinceModel.getCityList().add(cityModel);
        } else if (qName.equals("province")) {
        	provinceList.add(provinceModel);
        }
	}
	
	@Override
	public void characters(char[] ch, int start, int length)
			throws SAXException {
	}

}

通过XmlParserHandler.java提供的getDataList（）方法获取得到，之后再进行拆分放到省、市、区不同的HashMap里面方便做数据适配。

这里是它的具体实现代码：

protected void initProvinceDatas()
    {
        List provinceList = null;
        AssetManager asset = getAssets();
        try {
            InputStream input = asset.open("province_data.xml");
            // 创建一个解析xml的工厂对象
            SAXParserFactory spf = SAXParserFactory.newInstance();
            // 解析xml
            SAXParser parser = spf.newSAXParser();
            XmlParserHandler handler = new XmlParserHandler();
            parser.parse(input, handler);
            input.close();
            // 获取解析出来的数据
            provinceList = handler.getDataList();
            //*/ 初始化默认选中的省、市、区
            if (provinceList!= null && !provinceList.isEmpty()) {
                mCurrentProviceName = provinceList.get(0).getName();
                List cityList = provinceList.get(0).getCityList();
                if (cityList!= null && !cityList.isEmpty()) {
                    mCurrentCityName = cityList.get(0).getName();
                    List districtList = cityList.get(0).getDistrictList();
                    mCurrentDistrictName = districtList.get(0).getName();
                    mCurrentZipCode = districtList.get(0).getZipcode();
                }
            }
            //*/
            mProvinceDatas = new String[provinceList.size()];
            for (int i=0; i< provinceList.size(); i++) {
                mProvinceDatas[i] = provinceList.get(i).getName();
                List cityList = provinceList.get(i).getCityList();
                String[] cityNames = new String[cityList.size()];
                for (int j=0; j< cityList.size(); j++) {
                    cityNames[j] = cityList.get(j).getName();
                    List districtList = cityList.get(j).getDistrictList();
                    String[] distrinctNameArray = new String[districtList.size()];
                    DistrictModel[] distrinctArray = new DistrictModel[districtList.size()];
                    for (int k=0; k
                        DistrictModel districtModel = new DistrictModel(districtList.get(k).getName(), districtList.get(k).getZipcode());
                        mZipcodeDatasMap.put(districtList.get(k).getName(), districtList.get(k).getZipcode());
                        distrinctArray[k] = districtModel;
                        distrinctNameArray[k] = districtModel.getName();
                    }
                    mDistrictDatasMap.put(cityNames[j], distrinctNameArray);
                }
                mCitisDatasMap.put(provinceList.get(i).getName(), cityNames);
            }
        } catch (Throwable e) {
            e.printStackTrace();
        } finally {

        }
    }

protected void initProvinceDatas()
	{
		List provinceList = null;
    	AssetManager asset = getAssets();
        try {
            InputStream input = asset.open("province_data.xml");
            // 创建一个解析xml的工厂对象
			SAXParserFactory spf = SAXParserFactory.newInstance();
			// 解析xml
			SAXParser parser = spf.newSAXParser();
			XmlParserHandler handler = new XmlParserHandler();
			parser.parse(input, handler);
			input.close();
			// 获取解析出来的数据
			provinceList = handler.getDataList();
			//*/ 初始化默认选中的省、市、区
			if (provinceList!= null && !provinceList.isEmpty()) {
				mCurrentProviceName = provinceList.get(0).getName();
				List cityList = provinceList.get(0).getCityList();
				if (cityList!= null && !cityList.isEmpty()) {
					mCurrentCityName = cityList.get(0).getName();
					List districtList = cityList.get(0).getDistrictList();
					mCurrentDistrictName = districtList.get(0).getName();
					mCurrentZipCode = districtList.get(0).getZipcode();
				}
			}
			//*/
			mProvinceDatas = new String[provinceList.size()];
        	for (int i=0; i< provinceList.size(); i++) {
        		mProvinceDatas[i] = provinceList.get(i).getName();
        		List cityList = provinceList.get(i).getCityList();
        		String[] cityNames = new String[cityList.size()];
        		for (int j=0; j< cityList.size(); j++) {
        			cityNames[j] = cityList.get(j).getName();
        			List districtList = cityList.get(j).getDistrictList();
        			String[] distrinctNameArray = new String[districtList.size()];
        			DistrictModel[] distrinctArray = new DistrictModel[districtList.size()];
        			for (int k=0; k

在使用wheel组件时，数据适配起来也很方便，只需要做些数据、显示数量的配置即可，我这边设置了一行显示7条数据

initProvinceDatas();
        mViewProvince.setViewAdapter(new ArrayWheelAdapter(MainActivity.this, mProvinceDatas));
        // 设置可见条目数量
        mViewProvince.setVisibleItems(7);
        mViewCity.setVisibleItems(7);
        mViewDistrict.setVisibleItems(7);
        updateCities();
        updateAreas();

initProvinceDatas();
		mViewProvince.setViewAdapter(new ArrayWheelAdapter(MainActivity.this, mProvinceDatas));
		// 设置可见条目数量
		mViewProvince.setVisibleItems(7);
		mViewCity.setVisibleItems(7);
		mViewDistrict.setVisibleItems(7);
		updateCities();
		updateAreas();

要监听wheel组件的滑动、点击、选中改变事件，可以通过实现它的三个事件监听接口来实现，分别是：

1、OnWheelScrollListener 滑动事件：

/**
 * Wheel scrolled listener interface.
 */
public interface OnWheelScrollListener {
    /**
     * Callback method to be invoked when scrolling started.
     * @param wheel the wheel view whose state has changed.
     */
    void onScrollingStarted(WheelView wheel);

    /**
     * Callback method to be invoked when scrolling ended.
     * @param wheel the wheel view whose state has changed.
     */
    void onScrollingFinished(WheelView wheel);
}

/**
 * Wheel scrolled listener interface.
 */
public interface OnWheelScrollListener {
	/**
	 * Callback method to be invoked when scrolling started.
	 * @param wheel the wheel view whose state has changed.
	 */
	void onScrollingStarted(WheelView wheel);
	
	/**
	 * Callback method to be invoked when scrolling ended.
	 * @param wheel the wheel view whose state has changed.
	 */
	void onScrollingFinished(WheelView wheel);
}

2、OnWheelClickedListener 条目点击事件：

/**
 * Wheel clicked listener interface.
 * The onItemClicked() method is called whenever a wheel item is clicked
 *
 New Wheel position is set
 *
 Wheel view is scrolled
 */
public interface OnWheelClickedListener {
    /**
     * Callback method to be invoked when current item clicked
     * @param wheel the wheel view
     * @param itemIndex the index of clicked item
     */
    void onItemClicked(WheelView wheel, int itemIndex);
}

/**
 * Wheel clicked listener interface.
 * 
The onItemClicked() method is called whenever a wheel item is clicked
 * 
 New Wheel position is set
 * 
 Wheel view is scrolled
 */
public interface OnWheelClickedListener {
    /**
     * Callback method to be invoked when current item clicked
     * @param wheel the wheel view
     * @param itemIndex the index of clicked item
     */
    void onItemClicked(WheelView wheel, int itemIndex);
}

3、OnWheelChangedListener 被选中项的positon变化事件：

/**
 * Wheel changed listener interface.
 * The onChanged() method is called whenever current wheel positions is changed:
 *
 New Wheel position is set
 *
 Wheel view is scrolled
 */
public interface OnWheelChangedListener {
    /**
     * Callback method to be invoked when current item changed
     * @param wheel the wheel view whose state has changed
     * @param oldValue the old value of current item
     * @param newValue the new value of current item
     */
    void onChanged(WheelView wheel, int oldValue, int newValue);
}

/**
 * Wheel changed listener interface.
 * 
The onChanged() method is called whenever current wheel positions is changed:
 * 
 New Wheel position is set
 * 
 Wheel view is scrolled
 */
public interface OnWheelChangedListener {
	/**
	 * Callback method to be invoked when current item changed
	 * @param wheel the wheel view whose state has changed
	 * @param oldValue the old value of current item
	 * @param newValue the new value of current item
	 */
	void onChanged(WheelView wheel, int oldValue, int newValue);
}

这里只要知道哪个省、市、区被选中了，实现第三个接口就行，在方法回调时去作同步和更新数据，比如省级条目滑动的时候，市级和县级数据都要做对应的适配、市级滑动时需要去改变县级(区)的数据，这样才能实现级联的效果，至于如何改变，需要三个HashMap来分别保存他们的对应关系：

/**
     * key - 省 value - 市
     */
    protected Map mCitisDatasMap = new HashMap();
    /**
     * key - 市 values - 区
     */
    protected Map mDistrictDatasMap = new HashMap();

    /**
     * key - 区 values - 邮编
     */
    protected Map mZipcodeDatasMap = new HashMap();

/**
	 * key - 省 value - 市
	 */
	protected Map mCitisDatasMap = new HashMap();
	/**
	 * key - 市 values - 区
	 */
	protected Map mDistrictDatasMap = new HashMap();
	
	/**
	 * key - 区 values - 邮编
	 */
	protected Map mZipcodeDatasMap = new HashMap(); 

在onChanged()回调方法中，对于省、市、区/县的滑动，分别做数据的适配，代码如下：

@Override
    public void onChanged(WheelView wheel, int oldValue, int newValue) {
        // TODO Auto-generated method stub
        if (wheel == mViewProvince) {
            updateCities();
        } else if (wheel == mViewCity) {
            updateAreas();
        } else if (wheel == mViewDistrict) {
            mCurrentDistrictName = mDistrictDatasMap.get(mCurrentCityName)[newValue];
            mCurrentZipCode = mZipcodeDatasMap.get(mCurrentDistrictName);
        }
    }

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

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

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

@Override
	public void onChanged(WheelView wheel, int oldValue, int newValue) {
		// TODO Auto-generated method stub
		if (wheel == mViewProvince) {
			updateCities();
		} else if (wheel == mViewCity) {
			updateAreas();
		} else if (wheel == mViewDistrict) {
			mCurrentDistrictName = mDistrictDatasMap.get(mCurrentCityName)[newValue];
			mCurrentZipCode = mZipcodeDatasMap.get(mCurrentDistrictName);
		}
	}

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

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

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

综上代码，最终实现的界面截图：

源码下载地址：http://download.csdn.net/detail/wulianghuan/8205211