Question

我是cocos2d-x的新手，我跟着Cocos2d-x Game Development Essentials电子书，试图在iOS上制作演示应用。在它的指导的帮助下，但当我试图按照书中所写的方式在GameScreen.cpp文件中移动Astroids时，它们实际上并没有移动，我无法理解我缺少的是什么？

这是我使用的代码：

bool GameScene::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !Layer::init() )
    {
        return false;
    }
    //Add EVENT LISTENER TO HANDLE TOUCH EVENT,
    auto listener = EventListenerTouchOneByOne::create();
    listener->setSwallowTouches(true);
    listener->onTouchBegan      = CC_CALLBACK_2(GameScene::ontouchBegin,this);
    listener->onTouchMoved      = CC_CALLBACK_2(GameScene::ontouchMoved, this);
    listener->onTouchCancelled  = CC_CALLBACK_2(GameScene::ontouchCanceled, this);
    listener->onTouchEnded      = CC_CALLBACK_2(GameScene::ontouchEnded, this);
    this->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listener, this);
    istouching = false;
    touchPosition = 0;

    visibleSize = Director::getInstance()->getVisibleSize();
    origin = Director::getInstance()->getVisibleOrigin();

    auto backgroundSprite = Sprite::create("Game_Screen_Background.png");
    backgroundSprite->setPosition(Point((visibleSize.width/2)+origin.x,(visibleSize.height/2)+origin.y));
    this->addChild(backgroundSprite, -1);

    auto pauseItem =
    MenuItemImage::create("Pause_Button.png","Pause_Button(Click).png",CC_CALLBACK_1(GameScene::PushToGamePauseScene, this));
    pauseItem->setPosition(Point(pauseItem->getContentSize().width-(pauseItem->getContentSize().width/4)+origin.x,visibleSize.height - pauseItem->getContentSize().height +(pauseItem->getContentSize().width / 4) + origin.y));
    auto menu = Menu::create(pauseItem, NULL);
    menu->setPosition(Point::ZERO);
    this->addChild(menu);
    for (int i = 0; i < 2; i ++){
        backgroundSpriteArray[i] = Sprite::create("Game_Screen_Background.png");
        backgroundSpriteArray[i]->setPosition(Point((visibleSize.width/2)+origin.x,(-1*visibleSize.height*i)+(visibleSize.height/2)+origin.y));
        this->addChild(backgroundSpriteArray[i],-2);
    }
    playerSprite = Sprite::create("Space_Pod.png");
    playerSprite->setPosition(Point(visibleSize.width/2,pauseItem->getPosition().y-(pauseItem->getContentSize().height/2)-(playerSprite->getContentSize().height/2)));
    this->addChild(playerSprite, 1);
    this->schedule(schedule_selector(GameScene::spawnAsteroid), 1.0);
this->scheduleUpdate();
    return true;
}

以下是更新方法

void GameScene::update(float dt){
    Size visibleSize = Director::getInstance()->getVisibleSize();
    Point origin = Director::getInstance()->getVisibleOrigin();
    for (int i = 0; i < 2; i ++){
        if (backgroundSpriteArray[i]->getPosition().y >=visibleSize.height + (visibleSize.height / 2) -1){
            backgroundSpriteArray[i]->setPosition(Point((visibleSize.width / 2) + origin.x, (-1 *visibleSize.height) + (visibleSize.height / 2)));
        }
    }
    for (int i = 0; i < 2; i ++){
        backgroundSpriteArray[i]->setPosition(Point(backgroundSpriteArray[i]->getPosition().x,backgroundSpriteArray[i]->getPosition().y + (0.75 *visibleSize.height * dt)));
    }
    for (int i = 0; i < asteroids.size(); i++){
        asteroids[i]->setPosition(Point(asteroids[i]->getPosition().x,asteroids[i]->getPosition().y+(0.75 * visibleSize.height * dt)));
        if (asteroids[i]->getPosition().y > visibleSize.height * 2){
            this->removeChild(asteroids[i]);
            asteroids.erase(asteroids.begin() + i);
        }
    }
    //check for Touching
    if(istouching == true){
        //now check, which side of the screen is being touched
        if(touchPosition < visibleSize.width /2){
            //now, move the space pod to left
            float positionX = playerSprite->getPosition().x;
            playerSprite->setPositionX(positionX - (0.50* visibleSize.width * dt));
            positionX = playerSprite->getPositionX();

            //prevent space pod to getting off the screen (left side)
            if(positionX <= 0+(playerSprite->getContentSize().width/2))
            {
                playerSprite->setPositionX(playerSprite->getContentSize().width / 2);
            }
        }
        else{
            //now, move the space pod to right
            float positionX = playerSprite->getPositionX();
            playerSprite->setPositionX(positionX + (0.50 * visibleSize.width *dt));
            positionX = playerSprite->getPositionX();

            // check to prevent the space pod from going off the screen (right side)
            if(positionX >= visibleSize.width-(playerSprite->getContentSize().width/2))
            {
                playerSprite->setPositionX(visibleSize.width-(playerSprite->getContentSize().width/2));
            }
        }
    }
}

移动星号代码：

void GameScene::spawnAsteroid(float dt){
    Size visibleSize = Director::getInstance()->getVisibleSize();
    Point origin = Director::getInstance()->getVisibleOrigin();
    int asteroidIndex = (arc4random() % 3) + 1;
    __String* asteroidString = __String::createWithFormat("Asteroid_%i.png",asteroidIndex);
    auto *tempAsteroid = Sprite::create(asteroidString->getCString());
    int xRandomPosition = (arc4random() % (int)(visibleSize.width - (tempAsteroid->getContentSize().width / 2))) + (tempAsteroid->getContentSize().width / 2);
    tempAsteroid->setPosition(Point(xRandomPosition + origin.x, -tempAsteroid->getContentSize().height +origin.y));
    asteroids.push_back(tempAsteroid);
    this->update(touchPosition);
    this->addChild(asteroids[asteroids.size() - 1], -1);

}

该方法已在运行时调用，但不知道我的astroid对象没有移动任何人请帮助我解决问题以及如何解决它。

修改

好的，我把这个 - ＆gt; scheduleUpdate（）放在init（）中，然后开始在屏幕上移动astroids但是当我用touchBegin事件移动我的精灵（不是星形）时，astroid从屏幕上消失了。请指导我。

Answer 1

请将此行放在init方法

中

this->scheduleUpdate();

希望有所帮助

Answer 2

Sprite->runAction(Sequence::create(MoveTo::create(1.0f, Vec2(100,200)),NULL));

Sprite无法在cocos2d-x中移动

2 个答案: