关于label和MenuItemLabel的居中显示

Cocos2d-x
#1 
map_name_label = Label::createWithTTF(ttfConfig, "avgBgTitleLabel", TextHAlignment::CENTER, 0.6*GAME_WIN_WIDTH);//必须要有字，否则无法缩放
map_name_label->setPosition(Vec2(map_name_bg->getContentSize().width / 2, map_name_bg->getContentSize().height / 2));
map_name_bg->addChild(map_name_label, 2);
map_name_label->setAnchorPoint(Vec2(0.5, 0.5));

或者
map_name_label = Label::createWithTTF(ttfConfig, “avgBgTitleLabel”, TextHAlignment::CENTER, 0.6*GAME_WIN_WIDTH);//必须要有字，否则无法缩放
map_name_label->setScale(map_name_bg->getContentSize().height / 2 / map_name_label->getContentSize().height);

map_Item = MenuItemLabel::create(map_name_label, CC_CALLBACK_1(ScrollingBackground::showMiniMap, this));
map_Item->setPosition(Vec2(map_name_bg->getContentSize().width / 2, map_name_bg->getContentSize().height/2));
Menu* menu_mini = Menu::create(map_Item, NULL);//menu默认就是屏幕中心	
menu_mini->setPosition(Vec2::ZERO);//这个坐标是之前menu中所有按钮设定后的位移坐标
map_name_bg->addChild(menu_mini, 2);

只要把label放在MenuItemLabel里然后用MenuItemLabel设置坐标，显示出来就不会居中了，变得有偏理，如何用MenuItemLabel的同时还可以保证居中显示呢?