SpriteKit Obj C游戲在iOS 9中崩潰

Question

我有一個使用Sprite Kit和Objective-C的游戲，該游戲最初是使用Xcode 6和iOS 7開發的，但現在在iOS 9設備上崩潰。

當用戶從一個級別前進到另一個級別並將新的水平滾動背景（ SKNode ）添加到場景時，發生崩潰。

例外：

線程1 EXC_BAD_ACCESS（代碼= 1，地址= 0x0）

更改級別時，將水平滾動背景添加到場景：

// Array of planets to scroll
NSArray *parallaxBackgroundNames = @[@"bg_galaxy.png", @"bg_planetsunrise.png",
                                     @"bg_spacialanomaly.png", @"bg_spacialanomaly2.png"];
CGSize planetSizes = CGSizeMake(200.0, 200.0);


// Initialize new back round scrolling node and ad to scene 
_parallaxNodeBackgrounds = [[FMMParallaxNode alloc] initWithBackgrounds:parallaxBackgroundNames
                                                                   size:planetSizes
                                                   pointsPerSecondSpeed:10.0];

// Position in center of screen
_parallaxNodeBackgrounds.position = CGPointMake(self.size.width/2.0, self.size.height/2.0);

// Method to randomly place planets as offsets to center of screen
[_parallaxNodeBackgrounds randomizeNodesPositions];

// EXCEPTION THROWN HERE when adding it to the layer
[self addChild:_parallaxNodeBackgrounds];

_parallaxNodeBackgounds是SKSNode實例， FMMParallaxNode初始化為：

- (instancetype)initWithBackgrounds:(NSArray *)files size:(CGSize)size pointsPerSecondSpeed:(float)pointsPerSecondSpeed
{
    if (self = [super init])
    {
        _pointsPerSecondSpeed = pointsPerSecondSpeed;
        _numberOfImagesForBackground = [files count];
        _backgrounds = [NSMutableArray arrayWithCapacity:_numberOfImagesForBackground];
        _randomizeDuringRollover = NO;
        [files enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            SKSpriteNode *node = [SKSpriteNode spriteNodeWithImageNamed:obj];
            node.size = size;
            node.anchorPoint = CGPointZero;
            node.position = CGPointMake(size.width * idx, 0.0);
            node.name = @"background";
            //NSLog(@"node.position = x=%f,y=%f",node.position.x,node.position.y);
            [_backgrounds addObject:node];
            [self addChild:node];
        }];
    }
    return self;
}

關於此崩潰發生原因的任何輸入，我們深表感謝。

編輯：我對這個異常的理解是，如果指針指向已被釋放的內存或指針損壞，則拋出該異常。

當我在Xcode中進行構建和分析時，沒有與該對象相關的錯誤，並且我還在本地創建了一個新的指針（原始指針是一個實例var），但仍然遇到相同的錯誤。

Answer 1

像這樣做一個弱引用：

- (instancetype)initWithBackgrounds:(NSArray *)files size:(CGSize)size pointsPerSecondSpeed:(float)pointsPerSecondSpeed
{
    if (self = [super init])
    { 
        __weak FMMParallaxNode *weakSelf = self;
        _pointsPerSecondSpeed = pointsPerSecondSpeed;
        _numberOfImagesForBackground = [files count];
        _backgrounds = [NSMutableArray arrayWithCapacity:_numberOfImagesForBackground];
        _randomizeDuringRollover = NO;
        [files enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            SKSpriteNode *node = [SKSpriteNode spriteNodeWithImageNamed:obj];
            node.size = size;
            node.anchorPoint = CGPointZero;
            node.position = CGPointMake(size.width * idx, 0.0);
            node.name = @"background";
            //NSLog(@"node.position = x=%f,y=%f",node.position.x,node.position.y);
            [_backgrounds addObject:node];
            [weakSelf addChild:node];
        }];
    }
    return self;
}