Android Spinner 组件的应用实例

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"   xmlns:tools="http://schemas.android.com/tools"   android:layout_width="fill_parent"   android:layout_height="fill_parent"   android:orientation="vertical" >    <ScrollView     android:layout_width="wrap_content"     android:layout_height="wrap_content" >      <LinearLayout       android:layout_width="fill_parent"       android:layout_height="fill_parent"       android:gravity="center_horizontal"       android:orientation="vertical" >        <Spinner         android:id="@+id/spinner"         android:layout_width="300dp"         android:layout_height="wrap_content"         android:layout_gravity="center_vertical" />        <TextView         android:id="@+id/showInfo"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:layout_marginLeft="15dp"         android:layout_marginRight="15dp"         android:gravity="center"         android:text=" " />     </LinearLayout>   </ScrollView>  </LinearLayout> 

  package com.example.spinnertest;  import java.util.ArrayList;  import android.app.Activity; import android.content.res.Resources; 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 {    private Spinner spinner;   private TextView tx;   private ArrayList<String> list = null;   protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.main);      /* 获取TextView 实体对象 ， 用于显示星座的详细信息 */     tx = (TextView) findViewById(R.id.showInfo);      /* 下拉组件测试 Spinner 对象首先获取 */     spinner = (Spinner) findViewById(R.id.spinner);      /* 准备数据源 M , 用集合进行保存 */     list = new ArrayList<String>();      list.add("Aries");     list.add("Taurus");     list.add("Gemini");     list.add("Cancer");     list.add("Leo");     list.add("Virgo");     list.add("Libra");     list.add("Scorpio");     list.add("Sagittarius");     list.add("Capricorn");     list.add("Aquarius");     list.add("Pisces");       /* 实现M 层 与C 层的关系 ,绑定数据 */ /* 参数1：上下文对象； 参数2：系统资源布局方式 ； 参数3：数据对象 */     ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, list);      /* 对V 层和C 层进行关系的绑定； */     spinner.setAdapter(adapter);      spinner.setOnItemSelectedListener(new OnItemSelectedListener() {        /* 对所有的选择项进行监控 *//* 参3：当前选择项的ID 参4：被选择项在组中的位置，逻辑上与ID 相等，但代表的意义不一样 */       public void onItemSelected(AdapterView<?> arg0, View arg1,           int id, long position) {         // Toast.makeText(MainActivity.this, "你选择的是第:"+id+"值为："+list.get(id), 1000).show();                  /* 设置tx对象的值 */         String temp = getConstellation(id);         tx.setText("/t"+temp);        }        @Override       public void onNothingSelected(AdapterView<?> arg0) {         // TODO Auto-generated method stub        }     });     }    /* 显示星座的信息 */   protected String getConstellation(int id){     Resources rs = getResources();     String temp = "";     switch(id){     case 0:       temp = rs.getString(R.string.Aries);       break;     case 1:       temp = rs.getString(R.string.Taurus);       break;     case 2:       temp = rs.getString(R.string.Gemini);       break;     case 3:       temp = rs.getString(R.string.Cancer);       break;     case 4:       temp = rs.getString(R.string.Leo);       break;     case 5:       temp = rs.getString(R.string.Virgo);       break;     case 6:       temp = rs.getString(R.string.Libra);       break;     case 7:       temp = rs.getString(R.string.Scorpio);       break;     case 8:       temp = rs.getString(R.string.Sagittarius);       break;     case 9:       temp = rs.getString(R.string.Capricorn);       break;     case 10:       temp = rs.getString(R.string.Aquarius);       break;     case 11:       temp = rs.getString(R.string.Pisces);       break;     case 12:       temp = rs.getString(R.string.Aries);       break;     }     return temp;   }   }