<Spinner
        android:id="@+id/mySpinner"
        android:layout_height="wrap_content"
        android:layout_width="fill_parent"
        />

package com.example.spinner;

import android.app.Activity;
import android.os.Bundle;
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;

public class MainActivity extends Activity {

 private Spinner spinner;
 

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

  spinner = (Spinner)this.findViewById(R.id.mySpinner);
  //設置數據源
  String[] mydata = {"北京", "上海","廣東","廣西"};

  //聲明一個ArrayAdapter，并將數據源與之關聯起來
  ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,mydata);
  //設置彈出下拉列表的風格
  adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
  //將arrayAdapter對象添加進Spinner去
  spinner.setAdapter(adapter);
  //添加監聽器
  spinner.setOnItemSelectedListener(new OnItemSelectedListener() {

   @Override
   public void onItemSelected(AdapterView<?> arg0, View arg1,
     int arg2, long arg3) {
    Toast.makeText(MainActivity.this, "選擇了：" + arg2, Toast.LENGTH_SHORT).show();
   }

   @Override
   public void onNothingSelected(AdapterView<?> arg0) {
    // TODO Auto-generated method stub

   }
  });
 }
}