在ARC中启动一个新的Cocos2d-iPhone项目后获得内存警告。初学者

Question

最近一直在教自己目标-c来学习Cocos2d。

开始了一个新的项目，教自己的基本知识，与一个经典的陨石俄罗斯方块游戏。我采取的第一步是使用编辑>重构启用ARC项目，并在模板中选择最后4个文件。

到目前为止，已经能够通过子类CCSprite添加一个带有动态着色精灵的宝石，并将其沿XCoordinates移动，同时使其从顶部滑落。gems被赋予一个gemPos位置-例如5,3 -以便我以后实现匹配方法。

我收到了一个EXC_BAD_ACCESS警告，当几个模块在测试项目一段时间后互相叠加在一起时。我不明白，如果启用ARC，为什么会发生这种情况。

我笨拙的代码如下(遗漏了.h文件)：

默认helloworld层：

-(id) init
    {

        if( (self=[super init]) ) {

            oldGems = [[NSMutableArray alloc]init];

            [self setIsTouchEnabled:YES];

            [self newGem];

            [self scheduleUpdate];

        }
        return self;
    }

    - (void)registerWithTouchDispatcher
    {
        [[[CCDirector sharedDirector] touchDispatcher] addTargetedDelegate:self priority:0 swallowsTouches:YES];
    }

    - (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event
    {
        CGPoint touchLocation = [self convertTouchToNodeSpace:touch];
        oldPos = touchLocation;
        return TRUE;
    }

    - (void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event
    {
        CGPoint touchLocation = [self convertTouchToNodeSpace:touch];
        [self updateXCoord:(CGPoint)touchLocation];
    }

    - (void)updateXCoord:(CGPoint)touchLocation
    {


        CGPoint distance = ccpSub(touchLocation, oldPos);
        float xDistance = distance.x;

        if (abs(xDistance) >= 36) {
            if (touchLocation.x > oldPos.x) {
                [_thisGem setPosition:ccp([_thisGem position].x + 36, [_thisGem position].y)];
                [_thisGem setGemPos:ccp([_thisGem gemPos].x+1,[_thisGem gemPos].y)];
                NSLog(@"The gem position is %@", NSStringFromCGPoint([_thisGem gemPos]));
                oldPos = touchLocation;
            } else {
                [_thisGem setPosition:ccp([_thisGem position].x - 36, [_thisGem position].y)];
                [_thisGem setGemPos:ccp([_thisGem gemPos].x-1,[_thisGem gemPos].y)];
                NSLog(@"The gem position is %@", NSStringFromCGPoint([_thisGem gemPos]));
                oldPos = touchLocation;
            }
        }


    }

    - (void)newGem
    {
        if (_thisGem) {
            PCGem *oldGem = _thisGem;
            NSLog(@"Old gem position at %@", NSStringFromCGPoint([oldGem gemPos]));
            [oldGems addObject:oldGem];
        }

        _thisGem = [[PCGem alloc] initWithGemColor];
        [_thisGem setPosition:ccp(160, 450)];
        [self addChild:_thisGem];
        [_thisGem setGemPos:ccp(4,10)];

        NSLog(@"Gem added with %@ color", [_thisGem gemColorName]);
    }

    - (void)update:(ccTime)dt
    {

        if ([_thisGem gemPos].y > 0)  {

            [self spaceBelowOccupied];

            [_thisGem setPosition:ccp([_thisGem position].x, [_thisGem position].y-1)];
            [_thisGem setGemPos:ccp([_thisGem gemPos].x, floor([_thisGem position].y / 36))];

        } else {
            [self newGem];
        }
    }

    - (void)spaceBelowOccupied
    {    
            for (PCGem *occupiedTile in oldGems) {
                if (CGRectIntersectsRect(occupiedTile.boundingBox, _thisGem.boundingBox)) {
                    NSLog(@"Collision detected!");
                    [self newGem];
                }
            }
    }

和我笨拙的PCGem类：

    - (id)initWithGemColor
    {
        if ((self = [super initWithFile:@"gemGS.png"])) {


            NSArray *gemColorList = [NSArray arrayWithObjects:(NSString *)@"blue", (NSString *)@"red", (NSString *)@"green", nil];

            NSInteger randColor = arc4random_uniform(3);

            switch (randColor) {
                case 0:
                {
                    [self setGemColorName:[gemColorList objectAtIndex:0]];

                    ccColor3B gemColorRGB = {0,0,255};
                    [self setColor:gemColorRGB];
                    break;
                }
                case 1:
                {
                    [self setGemColorName:[gemColorList objectAtIndex:1]];

                    ccColor3B gemColorRGB = {255,0,0};
                    [self setColor:gemColorRGB];            
                    break;
                }
                case 2:
                {
                    [self setGemColorName:[gemColorList objectAtIndex:2]];

                    ccColor3B gemColorRGB = {0,255,0};
                    [self setColor:gemColorRGB];
                    break;
                }
            }

        }

        return self;

    }

这就引出了另一个问题，我似乎找不到答案。在启用ARC的Cocos2d项目的示例中，我看到了使用的节点方便方法，这当然是alloc]init]自动发布]。但我以为你不能在ARC上使用自动释放这会导致崩溃吗？这是怎么回事？

对我的痛苦有什么想法吗？将非常感谢澄清:)

干杯,

禤浩焯

Answer 1

我认为这可能是由于在枚举数组时编辑数组造成的。在您的更新函数中，您可以调用spaceBelowOccupied：

- (void)spaceBelowOccupied
{    
        for (PCGem *occupiedTile in oldGems) {
            if (CGRectIntersectsRect(occupiedTile.boundingBox, _thisGem.boundingBox)) {
                NSLog(@"Collision detected!");
                [self newGem];
            }
        }
}

然后，如果在for循环中调用newGem，则此循环成功：

if (_thisGem) {
        PCGem *oldGem = _thisGem;
        NSLog(@"Old gem position at %@", NSStringFromCGPoint([oldGem gemPos]));
        [oldGems addObject:oldGem];
    }

然后，在对数组进行枚举时，将对象添加到数组中。因此，将您的spaceBelowOccupied更改为此，并查看它是否有效：

 - (void)spaceBelowOccupied
{    
        for (PCGem *occupiedTile in [oldGems copy]) {
            if (CGRectIntersectsRect(occupiedTile.boundingBox, _thisGem.boundingBox)) {
                NSLog(@"Collision detected!");
                [self newGem];
            }
        }
}

这样，您就可以创建一个oldGems的副本来枚举它，一旦完成了它，就会自动释放它。