Spinner

package com.example.spinner;

import java.util.ArrayList;
import java.util.List;

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.TextView;

public class MainActivity extends Activity implements OnItemSelectedListener {

    private TextView textView;
    private Spinner spinner;
    private List<String> list;
    private ArrayAdapter<String> adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        textView = (TextView) this.findViewById(R.id.id_textView);
        spinner = (Spinner) this.findViewById(R.id.id_spinner);
        textView.setText("您选择的城市是北京");
        // 1.设置数据源
        list = new ArrayList<String>();
        list.add("北京");
        list.add("上海");
        list.add("广州");
        list.add("深圳");
        // 2.新建ArrayAdapter（数组适配器）
        adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, list);
        // 3.adapter设置一个下拉列表的样式
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_item);
        // 4.spinner加载适配器
        spinner.setAdapter(adapter);
        // 5.spinner设置监听器
        spinner.setOnItemSelectedListener(this);
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position,
            long id) {
        String cityName = adapter.getItem(position);
        // String cityName = list.get(position);
        textView.setText("您选择的城市是" + cityName);
    }

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

    }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=""
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/id_textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#ff0000"
        android:textSize="25sp" />

    <Spinner
        android:id="@+id/id_spinner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>