Android使用Spinner控件实现下拉列表的案例

<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" >
  <textview
    android:id="@+id/textview1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignparentleft="true"
    android:layout_alignparenttop="true"
    android:layout_margintop="46dp"
    android:text="所属城市"
    android:textsize="22sp" />
  <spinner
    android:id="@+id/spinner1"
    android:layout_width="200sp"
    android:layout_height="wrap_content"
    android:layout_alignparenttop="true"
    android:layout_margintop="44dp"
    android:layout_torightof="@+id/textview1" />
  <textview
    android:id="@+id/textview2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignright="@+id/textview1"
    android:layout_centervertical="true"
    android:text="所属星球" />
  <spinner
    android:id="@+id/spinner2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignleft="@+id/spinner1"
    android:layout_aligntop="@+id/textview2"
    android:layout_marginleft="21dp" />
</relativelayout>

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<string> 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<string>(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<string> getdatasource() {
 list<string> list = new arraylist<string>();
 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<?> 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<?> parent) {
 }
}

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <string name="app_name">spinners</string>
  <string name="action_settings">settings</string>
  <string name="hello_world">hello world!</string>
  <string-array name="planets_array">
    <item>mercury</item>
    <item>venus</item>
    <item>earth</item>
    <item>mars</item>
    <item>jupiter</item>
    <item>saturn</item>
    <item>uranus</item>
    <item>neptune</item>
  </string-array>
</resources>