在我的主场景中，我用这种方法创建了 4 堵墙：
-(void)createFirstWalls{
CGFloat maxY = CGRectGetMaxY(self.frame);
Wall* wall1=[Wall wallWithRect:self.frame color:[self randomColor] position:maxY andSpeed:speed];
Wall* wall2=[Wall wallWithRect:self.frame color:[self randomColor] position:maxY+distance andSpeed:speed];
Wall* wall3=[Wall wallWithRect:self.frame color:[self randomColor] position:maxY+distance*2 andSpeed:speed];
Wall* wall4=[Wall wallWithRect:self.frame color:[self randomColor] position:maxY+distance*3 andSpeed:speed];
wall1.name=@"1";
wall2.name=@"2";
wall3.name=@"3";
wall4.name=@"4";
[self addChild:wall1];
[self addChild:wall2];
[self addChild:wall3];
[self addChild:wall4];
}
输掉比赛后，我用经典的方式呈现另一个场景
SKScene* gameOver =[GameOver sceneWithSize:self.view.bounds.size];
gameOver.scaleMode = SKSceneScaleModeAspectFill;
[self.view presentScene:gameOver];
问题是，当我呈现新场景时，ARC 会取消分配我创建的所有墙，有时（或多或少有 40% 的机会）它会导致执行崩溃。
这是我的自定义 Wall 类：
#import "Wall.h"
static const uint32_t triangleCategory = 0x1 << 0;
static const uint32_t wallCategory = 0x1 << 1;
@implementation Wall
+(id)wallWithRect:(CGRect)rect color:(UIColor*)color position:(CGFloat)point andSpeed:(CGFloat)speed{
return [[Wall alloc] initWithRect:rect color:color position:point andSpeed:speed];
}
-(id)initWithRect:(CGRect)rect color:(UIColor*)color position:(CGFloat)point andSpeed:(CGFloat)speed{
if (self=[super init]) {
CGMutablePathRef path = CGPathCreateMutable();
CGPathMoveToPoint(path, nil, CGRectGetMinX(rect), 100);
CGPathAddLineToPoint(path, nil, CGRectGetMinX(rect), 115);
CGPathAddLineToPoint(path, nil, CGRectGetMaxX(rect), 115);
CGPathAddLineToPoint(path, nil, CGRectGetMaxX(rect), 100);
CGPathAddLineToPoint(path, nil, CGRectGetMinX(rect), 100);
self.position=CGPointMake(0, point);
self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
self.physicsBody.linearDamping=0;
self.physicsBody.affectedByGravity=NO;
self.physicsBody.velocity=CGVectorMake(0,speed);
self.physicsBody.collisionBitMask=0x0;
self.physicsBody.contactTestBitMask=triangleCategory;
self.physicsBody.categoryBitMask= wallCategory;
self.path=path;
CGPathRelease(path);
path = nil;
self.fillColor=color;
self.lineWidth=2;
self.strokeColor=[UIColor blackColor];
}
return self;
}
-(void)dealloc{
NSLog(@"Wall: %@",self.name);
}
@end
我创建了一个 dealloc 方法来看看会发生什么。 如果一切顺利，输出如下：
2014-08-19 15:56:42.252 running[36425:60b] Wall: 4
2014-08-19 15:56:42.256 running[36425:60b] Wall: 3
2014-08-19 15:56:42.257 running[36425:60b] Wall: 2
2014-08-19 15:56:42.260 running[36425:60b] Wall: 1
但是当崩溃时输出是这样的：
2014-08-19 15:57:37.767 running[36425:60b] Wall: 4
(lldb)
堆栈：
SpriteKit`SKCSprite::removeSubsprite(SKCSprite*):
0x331751a4: push {r4, r5, r7, lr}
0x331751a6: add r7, sp, #0x8
0x331751a8: sub sp, #0x4
0x331751aa: mov r4, r0
0x331751ac: add.w r0, r4, #0x1bc
0x331751b0: mov r5, sp
0x331751b2: str r1, [sp]
0x331751b4: mov r1, r5
0x331751b6: bl 0x33179b8c ; unsigned long std::__1::__tree<SKCSprite*, std::__1::less<SKCSprite*>, std::__1::allocator<SKCSprite*> >::__erase_unique<SKCSprite*>(SKCSprite* const&)
0x331751ba: add.w r0, r4, #0x190
0x331751be: mov r1, r5
0x331751c0: bl 0x33179760 ; std::__1::list<SKCSprite*, std::__1::allocator<SKCSprite*> >::remove(SKCSprite* const&)
0x331751c4: ldr r5, [sp]
0x331751c6: ldrb r0, [r5, #0xa]
0x331751c8: ldrh r1, [r5, #0x8]
0x331751ca: orr.w r0, r1, r0, lsl #16
0x331751ce: tst.w r0, #0x2
0x331751d2: bne 0x331751e4 ; SKCSprite::removeSubsprite(SKCSprite*) + 64
0x331751d4: ldr.w r1, [r5, #412]
0x331751d8: ldr r1, [r1, #0x8]
0x331751da: cmp r1, #0x0
0x331751dc: it eq
0x331751de: tsteq.w r0, #0x100
0x331751e2: beq 0x331751ec ; SKCSprite::removeSubsprite(SKCSprite*) + 72
0x331751e4: mov r0, r4
0x331751e6: mov r1, r5
0x331751e8: bl 0x33179798 ; SKCSprite::removeFromOffscreenList(SKCSprite*)
0x331751ec: movs r0, #0x0
0x331751ee: str.w r0, [r5, #332]
0x331751f2: ldr r0, [r5]
0x331751f4: ldr r1, [r0, #0x28]
0x331751f6: mov r0, r5
0x331751f8: blx r1
0x331751fa: ldrh r0, [r4, #0xc]
0x331751fc: orr r1, r0, #0x40
0x33175200: strh r1, [r4, #0xc]
0x33175202: ldr.w r0, [r4, #332]
0x33175206: cbz r0, 0x3317522c ; SKCSprite::removeSubsprite(SKCSprite*) + 136
0x33175208: add.w r1, r4, #0x14c
0x3317520c: ldrh r2, [r0, #0xc]
0x3317520e: orr r2, r2, #0x40
0x33175212: strh r2, [r0, #0xc] Thread 1: EXC_BAD_ACCESS(code=2, address=0x302e373d)
0x33175214: ldr r1, [r1]
0x33175216: ldrh r0, [r1, #0xc]
0x33175218: orr r0, r0, #0x40
0x3317521c: strh r0, [r1, #0xc]
0x3317521e: ldr.w r0, [r1, #332]
0x33175222: add.w r1, r1, #0x14c
0x33175226: cmp r0, #0x0
0x33175228: bne 0x3317520c ; SKCSprite::removeSubsprite(SKCSprite*) + 104
0x3317522a: ldrh r1, [r4, #0xc]
0x3317522c: orr r0, r1, #0x2
0x33175230: strh r0, [r4, #0xc]
0x33175232: b 0x33175236 ; SKCSprite::removeSubsprite(SKCSprite*) + 146
0x33175234: ldrh r0, [r4, #0xc]
0x33175236: tst.w r0, #0x80
0x3317523a: bne 0x3317524a ; SKCSprite::removeSubsprite(SKCSprite*) + 166
0x3317523c: orr r0, r0, #0x80
0x33175240: strh r0, [r4, #0xc]
0x33175242: ldr.w r4, [r4, #332]
0x33175246: cmp r4, #0x0
0x33175248: bne 0x33175234 ; SKCSprite::removeSubsprite(SKCSprite*) + 144
0x3317524a: add sp, #0x4
0x3317524c: pop {r4, r5, r7, pc}
0x3317524e: nop
我尝试了一些事情，比如在解除分配之前将物理体设置为零，但没有任何效果......有什么想法吗？
这似乎是 iOS 7.1 中 SKShapeNode 的一个错误......
但我终于找到答案了！！！希望这可以帮助更多的人。
我实现了一种方法来删除当前节点中的所有子节点
- (void)cleanUpChildrenAndRemove:(SKNode*)node {
for (SKNode *child in node.children) {
[self cleanUpChildrenAndRemove:child];
}
[node removeFromParent];
}
然后在呈现新场景之前调用该函数
[self cleanUpChildrenAndRemove:self]; //god bless this method
SKScene* gameOver =[GameOver sceneWithSize:self.view.bounds.size];
gameOver.scaleMode = SKSceneScaleModeAspectFill;
[self.view presentScene:gameOver];
不再有崩溃或 BAD_EXC...真正的奇迹。