Question

fresh to objC and cocos2d 🙂

i’m following “learn cocos2d game development with iOS5”, in chapter4, there is a “DoodleDrop” game.

define some variable in GameScene.h like this

@interface GameScene : CCLayer
{
    CCSprite *player;
    CGPoint playerVelocity;
    CCArray *spiders;
    CGSize screenSize;
    int dropedSpidersCount;
    float duration;
}
    + (CCScene *)scene;
@end

in GameScene.m the init method looks like this

- (id)init
{
    if (self = [super init]) {
        duration = 4.0;
        [self createPlayer]; 
        [self createSpiders]; // spiders were inited here.
        [self resetSpiders];
        [self schedule:@selector(chooseSpider:) interval:0.7];
    }
    return self;
}

while in chooseSpider, i cannot access spiders, xcode broke

in other methods, spiders or duration just behave normally, why does this happens?

---

gist code added

https://gist.github.com/2940466

Answer 1

After inspecting your code, I suggest you to try this fix:

- (void)createSpiders
{
CCSprite *tempSpider = [CCSprite spriteWithFile:@"spider.png"];
CGSize spiderSize = [tempSpider texture].contentSize;
int spiderCount = screenSize.width / spiderSize.width;
spiders = [[CCArray arrayWithCapacity:spiderCount] retain];

for (int i = 0; i < spiderCount; i++) {
    CCSprite *spider = [CCSprite spriteWithFile:@"spider.png"];
    [self addChild:spider];
    [spiders addObject:spider];
}
}

where the only difference is in the line:

spiders = [[CCArray arrayWithCapacity:spiderCount] retain];

Indeed, if you do not retain you spiders object, it will be autoreleased at the next run loop iteration.

OLD ANSWER:

Without seeing more code it is not possible to say exactly what is happening, but it seems that in the interval between creating the spiders and the actual execution of chooseSpiders, your spiders array gets deallocated.

As a quick try, I would suggest adding:

[spiders retain];

before calling

    [self schedule:@selector(chooseSpider:) interval:0.7];

and see wether the crash keeps happening.

if you provide more code, it could be possible to help you further.