CCMutableArray存不进东西？

Cocos2d-x
#1

//初始化，添加元素
_asteroids = new CCMutableArray<CCSprite *>();

for(int i = 0; i < KNUMASTEROIDS; ++i) {   
    CCSprite *asteroid = CCSprite::spriteWithSpriteFrameName("asteroid.png");      
    
    asteroid->setIsVisible(false) ; 
    
    _batchNode->addChild(asteroid); 
    
    _asteroids->addObject(asteroid); 
    
}

//update方法里刷新
float randMillisecs = randomValueBetween(0.20,1.0) * 1000;

    _nextAsteroidSpawn = randMillisecs + curTimeMillis; 
    
    float randY = randomValueBetween(0.0,winSize.height); 
    
    float randDuration = randomValueBetween(2.0,10.0); 
    
    CCSprite *asteroid = (CCSprite *)(_asteroids->getObjectAtIndex(_nextAsteroidSpawn)); 
    
    cout<<_asteroids->getObjectAtIndex(_nextAsteroidSpawn)<<endl;//输出全部是0
    
    _nextAsteroidSpawn++; 
    
    if (_nextAsteroidSpawn >= _asteroids->count()) 
        
        _nextAsteroidSpawn = 0; 
    
    
    if (asteroid) {//都是空，下面不执行
        asteroid->stopAllActions(); 
        
        asteroid->setPosition( ccp(winSize.width+asteroid->getContentSize().width/2, randY)); 
        
        asteroid->setIsVisible(true) ; 
        
        asteroid->runAction ( CCSequence::actions ( CCMoveBy::actionWithDuration(randDuration,ccp(-winSize.width-asteroid->getContentSize().width,0)) , 
                                                   
                                                   CCCallFuncN::actionWithTarget(this,callfuncN_selector(HelloWorld::setInvisible)) , 
                                                   
                                                   NULL // DO NOT FORGET TO TERMINATE WITH NULL (unexpected in C++) 
                                                   
                                                   ) ) ; 
        
    }

asteroid.png确实是有的，请问是什么问题？

#2

KNUMASTEROIDS和_nextAsteroidSpawn都是有值的

#3

额，弄出来了，2b了。。。nextAsteroidSpawn这玩意不是int类型