Spinner 下拉列表 demo

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <Spinner
    android:id="@+id/planets_spinner"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />
</LinearLayout>

public class MenuActivity extends Activity {
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_menu);
		Spinner spinner = (Spinner) findViewById(R.id.planets_spinner);
		// Create an ArrayAdapter using the string array and a default spinner layout
		ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
		        R.array.planets_array, android.R.layout.simple_spinner_item);
		// Specify the layout to use when the list of choices appears
		adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
		// Apply the adapter to the spinner
		spinner.setAdapter(adapter);
		spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
			public void onItemSelected(AdapterView<?> arg0, View arg1,
					int arg2, long arg3) {
				Log.i("onItemSelected",arg0+","+arg1+","+arg2+","+arg3);
			}
			public void onNothingSelected(AdapterView<?> arg0) {
				Log.i("onNothingSelected",arg0.toString());
			}
		});
	}
	
}

 http://developer.android.com/guide/topics/ui/controls/spinner.html#SelectListener