android中下拉框控件——Spinner

android中，用spinner控件很容易实现下拉框的功能。

下面是具体实现的步骤：

1. 在layout中添加spinner控件：
   

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

   
   
2. 在Activity中添加如下代码：
   

   	private static final String[] mAPDU={"0x00, 0x84, 0x00, 0x00, 0x08 ","0x00, 0xc0, 0x00, 0x00, 0x0a","..."};
   	private Spinner spinner;
   	private ArrayAdapter<String> adapter;
   	private static int mApduIndex = -1;
   
   
   
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           // TODO Auto-generated method stub
           super.onCreate(savedInstanceState);
           requestWindowFeature(Window.FEATURE_NO_TITLE);  
           setContentView(R.layout.iccard);
           mQuery = (EditText) findViewById(R.id.textViewQuery);
           mRuternData = (EditText) findViewById(R.id.textViewRuternData);
           spinner = (Spinner) findViewById(R.id.SpinnerAPDU);
   	//将可选内容与ArrayAdapter连接起来
   	adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,mAPDU);
   		
   	//设置下拉列表的风格
   	adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
   		
   	//将adapter 添加到spinner中
   	spinner.setAdapter(adapter);
   		
   	//添加事件Spinner事件监听  
   	spinner.setOnItemSelectedListener(new SpinnerSelectedListener(){});
   		
   	//设置默认值
   	spinner.setVisibility(View.VISIBLE);
   
   	
   	//使用数组形式操作
   	abstract class SpinnerSelectedListener implements OnItemSelectedListener{
   
   		public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
   				long arg3) {
   			mApduIndex = arg2;
   		}
   
   		public void onNothingSelected(AdapterView<?> arg0) {
   		}
   	}