添加子菜单

wang_peng1

import android.app.Activity;import android.os.Bundle;import android.view.Gravity;import android.view.Menu;import android.view.MenuItem;import android.view.SubMenu;import android.widget.Toast;/** * Class which shows how to work with Submenus * * @author FaYnaSoft Labs */public class Main extends Activity {private static final int FILE = 0;private static final int EDIT = 1;private static final int NEW_MENU_ITEM = Menu.FIRST;private static final int SAVE_MENU_ITEM = NEW_MENU_ITEM + 1;private static final int UNDO_MENU_ITEM = SAVE_MENU_ITEM + 1;private static final int REDO_MENU_ITEM = UNDO_MENU_ITEM + 1;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {SubMenu fileMenu = menu.addSubMenu("File");SubMenu editMenu = menu.addSubMenu("Edit");fileMenu.add(FILE, NEW_MENU_ITEM, 0, "new");fileMenu.add(FILE, SAVE_MENU_ITEM, 1, "save");editMenu.add(EDIT, UNDO_MENU_ITEM, 0, "undo");editMenu.add(EDIT, REDO_MENU_ITEM, 1, "redo");return super.onCreateOptionsMenu(menu);}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {switch (item.getItemId()) {case NEW_MENU_ITEM:showMsg("New");break;case SAVE_MENU_ITEM:showMsg("Save");break;case UNDO_MENU_ITEM:showMsg("Undo");break;case REDO_MENU_ITEM:showMsg("Redo");break;}return super.onOptionsItemSelected(item);}private void showMsg(String message) {Toast msg = Toast.makeText(Main.this, message, Toast.LENGTH_LONG);msg.setGravity(Gravity.CENTER, msg.getXOffset() / 2,msg.getYOffset() / 2);msg.show();}}  menu.add(0, ADD_MENU_ITEM, 0, "Add").setIcon(android.R.drawable.ic_menu_add);
menu.add(0, NEW_MENU_ITEM, 0, "New").setAlphabeticShortcut('N');