转：android上拉列表框 spinner

转载自：http://www.cnblogs.com/xinsheng/archive/2011/04/26/2029185.html

下拉菜单Spinner用法，效果图：

布局xml代码:

<Spinner android:id="@+id/sp1"	android:layout_width="fill_parent"	android:layout_height="wrap_content"	android:text="下拉菜单"	android:drawSelectorOnTop="true" 	android:prompt="@string/planet_prompt"/>

string.xml:

<string name="planet_prompt" >Choose a planet</string>

?最后是程序代码：

package com.pocketdigi; import java.util.List; import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.AdapterView;import android.widget.ArrayAdapter;import android.widget.Spinner;import android.widget.Toast;import android.widget.AdapterView.OnItemSelectedListener; public class main extends Activity {    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        SpDemo();    }    Spinner sp1;    ArrayAdapter<String> adapter;    List<String> allnum;    private static String[] arr={"1","2","3"};//定义一组选项    private static String[] Value={"我是1","我是2","我是3"};//定义选中后得到的值	private void SpDemo() {		//下面开始插入数据		sp1=(Spinner)findViewById(R.id.sp1);		adapter=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,arr);		//将可选内容与ArrayAdapter连接		adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);		//设置下拉列表的风格		sp1.setAdapter(adapter);		//将adapter添加到Spinner中		//插入数据结束		//下面开始获取选中的值		sp1.setSelection(2);		sp1.setOnItemSelectedListener(new OnItemSelectedListener(){			@Override 			public void onItemSelected(AdapterView<?> arg0, View arg1,					int arg2, long arg3) {				// TODO Auto-generated method stub				Toast.makeText(main.this, Value[arg2],10).show(); 			} 			@Override			public void onNothingSelected(AdapterView<?> arg0) {				// TODO Auto-generated method stub				Toast.makeText(main.this, "没选中",10).show();			} 		});	}}

上面代码中，插入数据那段，还可以用以下方法：
方法一，直接在程序中add

sp1=(Spinner)findViewById(R.id.sp1);adapter=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item);adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);adapter.add("1");adapter.add("2");adapter.add("3");sp1.setAdapter(adapter);

??方法二，把数据放入xml文件中

在res\layout目录下建立新的XML文件，文件名为Spinner.xml,内容如下：

<?xml version="1.0" encoding="utf-8"?><resources>     <string-array name="num">        <item>1</item>        <item>2</item>        <item>3</item>    </string-array></resources>

?主程序加入数据那段代码改为下面的代码：

sp1=(Spinner)findViewById(R.id.sp1);ArrayAdapter<CharSequence> Ad=ArrayAdapter.createFromResource(this, R.array.num,android.R.layout.simple_spinner_item);Ad.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);sp1.setAdapter(Ad);