Cocos2d-x学习笔记（七）菜单

菜单类继承关系如下：

图1 菜单类继承关系

文本菜单只能显示文本，包括：MenuItemLabel、MenuItemFont和MenuItemAtlasFont：

#include "HelloWorldScene.h"

USING_NS_CC;

Scene* HelloWorld::createScene()
{
    auto scene = Scene::create();
    auto layer = HelloWorld::create();
    scene->addChild(layer);
    return scene;
}

bool HelloWorld::init()
{
    if ( !Layer::init() )
    {
        return false;
    }
    
    Size visibleSize = Director::getInstance()->getVisibleSize();
    Vec2 origin = Director::getInstance()->getVisibleOrigin();

    Sprite *bg = Sprite::create("bg.jpg");
    bg->setPosition(Vec2(origin.x + visibleSize.width/2, origin.y + visibleSize.height/2));
    this->addChild(bg);

    MenuItemFont::setFontName("Times New Roman");
    MenuItemFont::setFontSize(80);
    MenuItemFont *item1 = MenuItemFont::create("Start", CC_CALLBACK_1(HelloWorld::menuItem1Callback, this));
　　MenuItemAtlasFont *item2 = MenuItemAtlasFont::create("Help", "fonts/tuffy_bold_italic-charmap.png",48, 65 ,' ', CC_CALLBACK_1(HelloWorld::menuItem2Callback, this));

    Menu *mn = Menu::create(item1, item2, NULL);
    mn->alignItemsVertically();
    this->addChild(mn);

    return true;
}

void HelloWorld::menuItem1Callback(cocos2d::Ref *pSender)
{
    MenuItem *item = (MenuItem*)pSender;
    log("Touch Start Menu Item %p", item);
}

void HelloWorld::menuItem2Callback(cocos2d::Ref *pSender)
{
    MenuItem *item = (MenuItem*)pSender;
    log("Touch Help Menu Item %p", item);
}

运行结果：

图2 文本菜单示例

精灵菜单和图片菜单，MenuItemImage继承于MenuItemSprite。

　　 Sprite *startSpriteNormal = Sprite::create("menu/start-up.png");
    Sprite *startSpriteSelected = Sprite::create("menu/start-down.png");

    MenuItemSprite *startMenuItem = MenuItemSprite::create(startSpriteNormal, startSpriteSelected, CC_CALLBACK_1(HelloWorld::menuItemStartCallback, this));
    startMenuItem->setPosition(Director::getInstance()->convertToGL(Vec2(700, 170)));

    MenuItemImage *settingMenuItem = MenuItemImage::create("menu/setting-up.png", "menu/setting-down.png", CC_CALLBACK_1(HelloWorld::menuItemSettingCallback, this));
    settingMenuItem->setPosition(Director::getInstance()->convertToGL(Vec2(480, 400)));

    MenuItemImage *helpMenuItem = MenuItemImage::create("menu/help-up.png", "menu/help-down.png", CC_CALLBACK_1(HelloWorld::menuItemHelpCallback, this));
    helpMenuItem->setPosition(Director::getInstance()->convertToGL(Vec2(860, 480)));

    Menu *mu = Menu::create(startMenuItem, settingMenuItem, helpMenuItem, NULL);
    mu->setPosition(Vec2::ZERO);
    this->addChild(mu);

运行结果：

图3 精灵菜单和图片菜单示例

 开关菜单，它可以进行两种状态切换的菜单项：

auto soundOnMenuItem = MenuItemImage::create("menu2/on.png", "menu2/on.png");
    auto soundOffMenuItem = MenuItemImage::create("menu2/off.png", "menu2/off.png");

    auto soundToggleMenuItem = MenuItemToggle::createWithCallback(CC_CALLBACK_1(HelloWorld::menuSoundToggleCallback, this), soundOnMenuItem, soundOffMenuItem, NULL);
    soundToggleMenuItem->setPosition(Director::getInstance()->convertToGL(Vec2(818, 220)));

    auto musicOnMenuItem = MenuItemImage::create("menu2/on.png", "menu2/on.png");
    auto musicOffMenuItem = MenuItemImage::create("menu2/off.png", "menu2/off.png");

    auto musicToggleMenuItem = MenuItemToggle::createWithCallback(CC_CALLBACK_1(HelloWorld::menuMusicToggleCallback, this), musicOnMenuItem, musicOffMenuItem, NULL);
    musicToggleMenuItem->setPosition(Director::getInstance()->convertToGL(Vec2(818, 362)));

    auto okMenuItem = MenuItemImage::create("menu2/ok-down.png", "menu2/ok-up.png");
    okMenuItem->setPosition(Director::getInstance()->convertToGL(Vec2(600, 510)));

    Menu *mn = Menu::create(soundToggleMenuItem, musicToggleMenuItem, okMenuItem, NULL);
    mn->setPosition(Vec2::ZERO);
    this->addChild(mn);

运行结果：

图4 开关菜单