子菜单

public class MainActivity extends Activity {
	
	private static final int ITEM1 = Menu.FIRST;
	private static final int ITEM2 = Menu.FIRST+1;
	
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

	/**
  * 覆盖该方法添加子菜单项
  */
 public boolean onCreateOptionsMenu(Menu menu) {
  SubMenu file = menu.addSubMenu("文件");
  SubMenu edit = menu.addSubMenu("編輯");
  file.add(0, ITEM1, 0, "新建");
  file.add(0, ITEM2, 0, "打开");
  return true;
 }
        
    /**
     * 覆盖该方法，响应菜单选项被单击事件
     */
    public boolean onOptionsItemSelected(MenuItem item) {
    	switch (item.getItemId()) {
		case ITEM1:
			setTitle("新建文件！");
			break;
		case ITEM2:
			setTitle("打开文件！");
			break;
		}
    	return true;
    }
}