ios - 当我们将 nil 指向 sprite 节点时会发生什么？

Question

@interface Player()
@property (nonatomic) SKTextureAtlas *atlas;
@end
@implementation Player{
    DecorativeBall *decorativeBall; 
    GolfBall *golfBall; 
}
- (id) initWithBallName :(NSString *) name{
    if(self = [super init]){
        _atlas = [SKTextureAtlas atlasNamed:@"Balls"];
        [self removeAllChildren];
        if ([name isEqualToString:@"DecorativeBall"]) // if it is a decorative ball{
            if (debug){
                printf("\n\n It's a Decorative ball");
            }
            if (!decorativeBall){
                 decorativeBall = [[DecorativeBall alloc] initWithTexture:[_atlas textureNamed:@"DecorativeBall"]];
                golfBall = nil;
            }
            [self addChild:decorativeBall];
        }
        if ([name isEqualToString:@"GolfBall"]) // if it is a golf ball{
            if (debug){
                printf("\n\n It's a Golf ball");
            }
            if (!golfBall){
                golfBall = [[GolfBall alloc] initWithTexture:[_atlas textureNamed:@"GolfBall"]];
                decorativeBall = nil;
            }
            [self addChild:golfBall];
        }
    }
    return self;
}
@end

从上面的代码 decorativeBall = nil 和 golfBall = nil 来看，它有助于释放内存还是有意义？ 我想做的是，如果已经选择了高尔夫球，现在如果玩家将其切换为装饰球。我想从现场移除高尔夫球，这是正确的方法吗？

Answer 1

我假设 DecorativeBall 和 GolfBall 都是 SKSpriteNode 的子类并且您正在使用 ARC。

由于 ARC，golfBall = nil; 确实释放了 sprite 但这还不够，至少还有一个对它的引用:您首先需要通过调用 从层次结构中删除它>[golfBall removeFromParent];。当然，decorativeBall 也是如此。