Android_Spinner_Listener

xml布局文件：

<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"

       android:layout_width="wrap_content"

       android:layout_height="wrap_content"/>

   <Button

       android:id="@+id/btn_notity"

       android:layout_width="match_parent"

       android:layout_height="wrap_content"

       android:layout_below="@id/spinner"

       android:layout_marginTop="10dp"

       android:text="更新列表"

       android:textSize="20sp"/>

</RelativeLayout>

spinner_item文件：

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="horizontal" >

    <ImageView

        android:id="@+id/iamge"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        />

    <TextView

        android:id="@+id/text"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"/>

</LinearLayout>

源代码：

package com.example.day04_spinnerlistener;

import java.util.ArrayList;

import android.os.Bundle;

import android.app.Activity;

import android.util.Log;

import android.view.Menu;

import android.view.View;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemSelectedListener;

import android.widget.ArrayAdapter;

import android.widget.Button;

import android.widget.Spinner;

public class MainActivity extends Activity implements View.OnClickListener{

    private Spinner spinner;

    private String TAG = "MainActivity";

    private String[] cities;

    private ArrayAdapter<String> adapter;

    private Button button;

    private ArrayList<String> cityList;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        button = (Button) findViewById(R.id.btn_notity);

        button.setOnClickListener(this);

        spinner = (Spinner) findViewById(R.id.spinner);

        cities = new String[] {"北京","上海","广州","杭州","天津"};

        cityList = new ArrayList<String>();

        for (int i = 0; i < cities.length; i++) {

            cityList.add(cities[i]);

        }

        adapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_dropdown_item_1line, cityList);

        spinner.setAdapter(adapter);

        spinner.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override

            public void onItemSelected(AdapterView<?> parent, View view,

                    int position, long id) {

                // TODO Auto-generated method stub

                //如何获取被点击的item对应的数据

                //通过数据源数组获得该索引的数据

                String name1 = cities[position];

                //通过适配器获取索引条目的数据

                String name2 = adapter.getItem(position);

                //通过spinner(适配器控件)获取该索引位置条目的数据

                String name3 = spinner.getItemAtPosition(position).toString();

                Log.i(TAG ,position+"name1:"+name1+"name2,"+name2+",name3:"+name3 );

            }

            @Override

            public void onNothingSelected(AdapterView<?> parent) {

                // TODO Auto-generated method stub

            }

        });

    }

    /**

     * 当点击更新按钮，触发监听事件，执行更新数据的操作

     */

    @Override

    public void onClick(View v) {

        // TODO Auto-generated method stub

        ArrayList<String> newList = new ArrayList<String>();

        for (int i = 0; i < 10; i++) {

            newList.add("item "+i);

        }

        //清空数据

//        cityList.removeAll(cityList);

        //添加新的数据到原数据中

        cityList.addAll(newList);

        //通知更新数据

        adapter.notifyDataSetChanged();

    }

}