Android_Spinner_example

xml数据：

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:padd<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Spinner
        android:id="@+id/spinner_city"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</RelativeLayout>ingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Spinner
        android:id="@+id/spinner_city"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</RelativeLayout>

源代码：

package com.example.day04_work1;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.util.Xml;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.Spinner;
/**
 * 将文件weathercity.xml数据中的省份显示在下拉列表中
 * 1.将文件中的数据读取出来
 * 2.解析数据，将数据存到集合（数据源）
 * 3.下拉列表设置适配器，将集合作为数据源放入适配器
 */
public class MainActivity extends Activity {

    private Spinner spinner;
    private String TAG = "info";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        spinner = (Spinner) findViewById(R.id.spinner_city);
        String data = getStringFromFile();
        if(data != null && data.length() != 0){
            //准备数据源
            List<String> list = parsexmlToList(data);
            //创建适配器
            ArrayAdapter<String> adapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_dropdown_item_1line, list);
            //设置适配器
            spinner.setAdapter(adapter);
        }

    }
/**
 * 解析xml数据到集合
 * @param data
 * @return
 */
    private List<String> parsexmlToList(String data) {
        // TODO Auto-generated method stub
        try {
            List<String> list = new ArrayList<String>();
            //获取xml解析器
            /**
             * 三种方式：
             * 1.在res目录中的xml目录中的xml文件：XmlPullParser parser = getResource().getXml(R.xml.citys_weather.xml);
             * 2.XmlPullParser parser = Xml.newPullParser();
             * 3.XmlPullParser parser = XmlPullParserFactory.newInstance().newPullParser();
             */
            XmlPullParser parser = Xml.newPullParser();
            //设置数据源
            parser.setInput(new StringReader(data));
            //得到事件码
            int code = parser.getEventType();
            while((code!=XmlPullParser.END_DOCUMENT)){
                String name = parser.getName();
                switch (code) {
                case XmlPullParser.START_TAG:
                    if("pn".equals(name)){
                        list.add(parser.nextText());
                    }
                    break;

                default:
                    break;
                }
                code = parser.next();
            }
            return list;
        } catch (XmlPullParserException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return null;
    }
/**
 * 从文件获取xml数据
 * @return
 */
    private String getStringFromFile() {
        InputStream is = null;
        ByteArrayOutputStream baos = null;
        try {
        //将asserts目录中的文件转换成输入流
        is = getResources().getAssets().open("citys_weather.xml");
        baos = new ByteArrayOutputStream();
        int len = 0;
        byte[] buf = new byte[1024*1024];
        while(-1!=(len = is.read(buf))){
            baos.write(buf, 0, len);
            baos.flush();
        }
        return new String(baos.toByteArray());
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }finally{
        try {
            if(baos!=null){
                baos.close();
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            if(is!=null){
                is.close();
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
        return null;

    }

}