雪碧在茧里不能动

我是cocos2d-x的新手，我遵循了Cocos2d-x Game Development EssentialsEbook，并试图在iOS中制作演示应用程序。在它的指导下，但当我试图像书中所写的那样在GameScreen.cpp文件中移动Astroids时，它们实际上并没有移动，我不明白我错过了什么？

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));
}
}
}
}

移动天体代码：

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);
}

这个方法在运行时被调用了，但不知道我的天体并没有移动，有人能帮我解决这个问题以及如何解决它吗？

编辑

好的，我把这个->scheduleUpdate()放在init()中，并开始在屏幕上移动天体，但当我用touchBegin事件移动我的精灵(而不是天体)时，天体从屏幕上消失了。请指导我。