Android使用Spinner控件实现下拉列表的案例

package com.example.spinners;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
/**
 * 通过继承OnItemSelectedListener接口来实现选择时的事件
 * @author xuliugen
 *
 */
public class MainActivity extends Activity implements OnItemSelectedListener {
 private Spinner spinner1;
 private Spinner spinner2;
 // private SpinnerAdapter spinnerAdapter;
 private ArrayAdapter adapter;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 spinner1 = (Spinner) this.findViewById(R.id.spinner1);
 spinner2 = (Spinner) this.findViewById(R.id.spinner2);
 // 第一种手工输入的list
 adapter = new ArrayAdapter(MainActivity.this,
  android.R.layout.simple_spinner_item, getDataSource());
 spinner1.setAdapter(adapter);
 //注册监听器
 spinner1.setOnItemSelectedListener(this);
 // 第二种：通过加载xml文件配置的数据源
 ArrayAdapter adapter2 = ArrayAdapter.createFromResource(this,
  R.array.planets_array, android.R.layout.simple_spinner_item);
 adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
 spinner2.setAdapter(adapter2);
 }
 /*
 * 通过第一种方法：手工输入的list
 */
 public List getDataSource() {
 List list = new ArrayList();
 list.add("beijing");
 list.add("beida");
 list.add("shahai");
 list.add("shangjing");
 list.add("shanglian");
 list.add("chengdu");
 return list;
 }
 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
 getMenuInflater().inflate(R.menu.main, menu);
 return true;
 }
 @Override
 public void onItemSelected(AdapterView<&＃63;> parent, View view, int position,
  long id) {
 String itemString = spinner1.getItemAtPosition(position).toString();
 Toast.makeText(this, "你选中的是" + itemString, 1).show();
 }
 @Override
 public void onNothingSelected(AdapterView<&＃63;> parent) {
 }
}

<&＃63;xml version="1.0" encoding="utf-8"&＃63;>

  Spinners
  Settings
  Hello world!
  
    Mercury
    Venus
    Earth
    Mars
    Jupiter
    Saturn
    Uranus
    Neptune