android 30 下拉列表框：ArrayAdapter和Spinner.

package com.sxt.day05_04;

import android.os.Bundle;
import android.app.Activity;
import android.content.res.Resources;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
import android.widget.AdapterView.OnItemSelectedListener;

public class MainActivity extends Activity implements OnItemSelectedListener{
    Spinner mspinYear,mspinMonth;
    ArrayAdapter<CharSequence> mAdapterYear,mAdapterMonth;
    String[] mYears,mMonths,mDays;
    int mYear=2000;//初始年份
    int mMonth=1;//初始月份

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        initView();
    }

    private void initView() {
        mspinYear=(Spinner) findViewById(R.id.spinYear);
        //给mspinYear创建一个适配器，R.array.years是要加入进去的字符串数组资源，android.R.layout.simple_list_item_1是显示的列表项
        mAdapterYear=ArrayAdapter.createFromResource(this, R.array.years, android.R.layout.simple_list_item_1);
        //设置适配器
        mspinYear.setAdapter(mAdapterYear);
        mspinYear.setOnItemSelectedListener(this);

    }

    private void initData() {
        Resources res = getResources();//获取资源中定义的数组
        mYears=res.getStringArray(R.array.years);
        mMonths=res.getStringArray(R.array.months);
        mDays=res.getStringArray(R.array.days);
    }

    @Override
    //parent是Spinner，view是点击的某一项，
    public void onItemSelected(AdapterView<?> parent, View view, int position,
            long id) {
        switch (parent.getId()) {
        case R.id.spinYear:
            mYear=Integer.parseInt(mYears[position]);
            if(mMonth==2&&(mYear%400==0 || mYear%4==0 && mYear%100!=0)){
                Toast.makeText(MainActivity.this, mDays[0]+"天", 2000).show();
            }else{
                Toast.makeText(MainActivity.this, mDays[mMonth], 2000).show();
            }
            break;
        case R.id.spinMonth:

            break;
        }
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
        // TODO Auto-generated method stub

    }

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/tvYear"
        android:layout_marginTop="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="选择年份" />
    <Spinner
        android:id="@+id/spinYear"
        android:layout_toRightOf="@id/tvYear"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:prompt="@string/prompt_year"
        android:spinnerMode="dialog"/>             下拉之后以dialog对话框显示
    <TextView
        android:id="@+id/tvMonth"
        android:layout_marginTop="10dp"
        android:layout_below="@id/spinYear"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="选择月份" />
    <Spinner
        android:id="@+id/spinMonth"
        android:layout_toRightOf="@id/tvMonth"
        android:layout_below="@id/spinYear"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:prompt="@string/prompt_year"
        android:spinnerMode="dialog"/>             下拉之后以dialog对话框显示  

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Day05_04-ArrayAdapterAndSpinnerDemo</string>
    <string name="action_settings">Settings</string>
    <string name="prompt_year">选择年份</string>
    <string name="prompt_month">选择月份</string>
    <string-array name="years">
        <item>2000</item>
        <item>2001</item>
        <item>2002</item>
        <item>2003</item>
        <item>2004</item>
        <item>2005</item>
        <item>2006</item>
        <item>2007</item>

    </string-array>
    <string-array name="months">
        <item>1</item>
        <item >2</item>
        <item >3</item>
        <item >4</item>
        <item >5</item>
        <item >6</item>
        <item >7</item>
        <item >8</item>
        <item >9</item>
        <item >10</item>
        <item >11</item>
        <item >12</item>

    </string-array>
    <string-array name="days">
        <item >29</item>
        <item >31</item>
        <item >28</item>
        <item >31</item>
        <item >30</item>
        <item >31</item>
        <item >30</item>
        <item >31</item>
        <item >31</item>
        <item >30</item>
        <item >31</item>
        <item >30</item>
        <item >31</item>

    </string-array>
</resources>