public class MainActivity extends Activity {
 private static final String[] bloodType = {"O型","A型","B型","AB型","其他",};
	private TextView textView;
	private Spinner spinner;
	private ArrayAdapter adapter;
	
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        textView = (TextView) findViewById(R.id.text);
        spinner = (Spinner) findViewById(R.id.spinner);
        //將可選內容和ArrayAdapter連接
        adapter = new ArrayAdapter(this,android.R.layout.simple_spinner_item,bloodType);
        //將adapter添加到spinner中
        spinner.setAdapter(adapter);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setOnItemSelectedListener(new OnItemSelectedListener(){
			@Override
			public void onItemSelected(AdapterView<?> arg0, View arg1,
					int arg2, long arg3) {
				textView.setText("您的血型是"+bloodType[arg2]);
				arg0.setVisibility(View.VISIBLE);
			}
			@Override
			public void onNothingSelected(AdapterView<?> arg0) {
				//沒有選中
			}
        	
        });
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
XML文件:
<LinearLayout 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/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    <Spinner 
        android:id="@+id/spinner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"/>
</LinearLayout>
}
原文:http://www.cnblogs.com/Smart-Du/p/4302009.html