android:自定义spinner下拉框

在项目中，下拉框所展示的信息无法满足用户需求时，需要用户自己手动输入，并且需要在下次以下拉是将上次输入的数据显示出来。下面通过spinner+edittext来实现输入，用xml将数据存储下来。

下面是实现功能截图：

当选择“请输入”时，用户自己输入地址

下一次在打开下拉框时：

具体的实现代码如下：
MainActivity .java

public class MainActivity extends Activity {    Spinner  spinner1;    EditText edittext;    private ArrayAdapter<String> mAdapter;    private List<String> Counties=new ArrayList<String>();    private List<County> mcounties;    String path=Environment.getExternalStorageDirectory().toString()+"/county.xml";    XMLService  xmlService;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        //获取城市数据        xmlService=new XMLService();        try {            mcounties=xmlService.getCounties(path);            Log.i("Test", mcounties.size()+"");        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        spinner1=(Spinner)findViewById(R.id.spinner1);        edittext=(EditText) findViewById(R.id.edittext);        if(mcounties!=null){            for(int i=0;i<mcounties.size();i++){                Counties.add(mcounties.get(i).getName());            }        }        mAdapter=new ArrayAdapter<String>(MainActivity.this,android.R.layout.simple_spinner_item,Counties);        mAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);        spinner1.setAdapter(mAdapter);        spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {            @Override            public void onItemSelected(AdapterView<?> adapter, View view,                    int position, long id) {                // TODO Auto-generated method stub                String str=(String)spinner1.getAdapter().getItem((int)id);                if(str.equals("请输入")){                    edittext.setVisibility(View.VISIBLE);                    spinner1.setVisibility(View.GONE);                }            }            @Override            public void onNothingSelected(AdapterView<?> arg0) {                // TODO Auto-generated method stub            }        });    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.main, menu);        return true;    }    public void Goto(View v){        //在这里将新编辑的数据加入到county.xml中        String s=edittext.getText().toString();        if(!s.equals("")){            int tmp=mcounties.size();            County  tmpcounty=new County(tmp, s);            List<County> tmpcounties=new ArrayList<County>();              for (int i = 0; i < mcounties.size()+1; i++) {                if(i<tmp-1){                    tmpcounties.add(mcounties.get(i));                }                if(i==tmp-1){                    tmpcounties.add(tmpcounty);                }                if(i==tmp){                    County  tmpcounty1=new County(tmp+1, mcounties.get(i-1).getName());                    tmpcounties.add(tmpcounty1);                }            }            File file=new File(path);            file.delete();            File xmlFile = new File(Environment.getExternalStorageDirectory().toString(), "county.xml");            Log.i("Test", Environment.getExternalStorageDirectory().toString());            FileOutputStream outStream = null;            try {                outStream = new FileOutputStream(xmlFile);                for(County county:tmpcounties){                    Log.i("Test", county.getName());                }                xmlService.NewXML(tmpcounties, outStream);            } catch (Exception e) {                // TODO Auto-generated catch block                e.printStackTrace();            }finally{                try {                    outStream.close();                } catch (IOException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }        }else{            Toast.makeText(getApplicationContext(), "请输入地址", Toast.LENGTH_LONG).show();        }    }}

County.java

package com.example.domain;public class County {    int id;    String name;    public County() {        super();    }    public County(int id, String name) {        super();        this.id = id;        this.name = name;    }    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

XMLService.java

package com.example.service;import java.io.File;import java.io.FileInputStream;import java.io.InputStream;import java.io.OutputStream;import java.util.ArrayList;import java.util.List;import org.xmlpull.v1.XmlPullParser;import org.xmlpull.v1.XmlSerializer;import com.example.domain.County;import android.annotation.SuppressLint;import android.util.Xml;@SuppressLint("UseValueOf")public class XMLService {    /**     * 查询XML文件下的数据     * @param path  文件路径     * @return     * @throws Exception     */    public List<County>  getCounties(String path)   throws  Exception{        File file=new File(path);        InputStream in=new FileInputStream(file);        List<County>  counties =null;        County county=null;        XmlPullParser pullParser = Xml.newPullParser();        pullParser.setInput(in, "UTF-8");        int event = pullParser.getEventType();        while(event != XmlPullParser.END_DOCUMENT){            switch (event) {            case XmlPullParser.START_DOCUMENT:                counties = new ArrayList<County>();                break;            case XmlPullParser.START_TAG:                if("county".equals(pullParser.getName())){                    int id = new Integer(pullParser.getAttributeValue(0));                    county = new County();                    county.setId(id);                }                if("name".equals(pullParser.getName())){                    String name = pullParser.nextText();                    county.setName(name);                }                break;            case XmlPullParser.END_TAG:                if("county".equals(pullParser.getName())){                    counties.add(county);                    county = null;                }                break;            }            event = pullParser.next();        }        return counties;    }       /**     *重新生成XML文件     * @param counties     * @param out     * @throws Exception     */    public void NewXML(List<County> counties, OutputStream out) throws Exception{        XmlSerializer serializer = Xml.newSerializer();        serializer.setOutput(out, "UTF-8");        serializer.startDocument("UTF-8", true);        serializer.startTag(null, "counties");        for(County county : counties){            serializer.startTag(null, "county");            serializer.attribute(null, "id", county.getId()+"");            serializer.startTag(null, "name");            serializer.text(county.getName());            serializer.endTag(null, "name");            serializer.endTag(null, "county");        }        serializer.endTag(null, "counties");        serializer.endDocument();        out.flush();        out.close();    }}

在SDcard下–county.xml：

<?xml version='1.0' encoding='UTF-8' standalone='yes' ?><counties>    <county id="1">      <name>北京</name>    </county>    <county id="2">      <name>西安</name>    </county>    <county id="3">      <name>上海</name>    </county>    <county id="4">      <name>惠州</name>    </county>    <county id="5">      <name>请输入</name>    </county></counties>