ActionBar的使用——下拉菜单操作

示例代码如下：

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        SpinnerAdapter adapter = ArrayAdapter.createFromResource(this, 
        		R.array.student, android.R.layout.simple_spinner_dropdown_item);
        
        ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);
        actionBar.setListNavigationCallbacks(adapter, new OnNavigationListener() {

			@Override
			public boolean onNavigationItemSelected(int itemPosition, long itemId) {
				// TODO Auto-generated method stub
				return false;
			}
        	
        });
    }