我只是在玩泄漏并试图故意创造一个.所以,即使做这样的事情也很愚蠢：
class LeakingObjectA{
var strongRefToB:LeakingObjectB?
deinit{ print("LeakingObjectA deinit")}
}
class LeakingObjectB{
var strongRefToA:LeakingObjectA?
deinit{ print("LeakingObjectB deinit")}
}
这对于科学目的来说很好,这创造了一个强大的参考周期.
现在在didMovetoView里面我声明了局部常量并像这样发生泄漏：
override func didMovetoView(view: SKView) {
let a = LeakingObjectA()
let b = LeakingObjectB()
a.strongRefToB = b
b.strongRefToA = a
}
转换到另一个场景后,正确调用场景的deinit,但实际上并未调用a和b实例的deinit.
另外我说泄漏,因为这实际上是在仪器中检测到泄漏：
现在,如果我将这两个本地变量声明为场景的属性,则仪器检测到泄漏之间存在差异：
class GameScene:SKScene {
let a = LeakingObjectA()
let b = LeakingObjectB()
//...later in didMovetoView method I make a strong reference cycle like from the example above
}
当然在这种情况下,在转换之后也会调用场景的deinit,并且与上面相同,不会调用a和b实例的deinit(因为强引用循环).
尽管如此,仪器中没有检测到泄漏……那么对此有什么合理的解释呢？
解决方法
我无法使用下面的代码复制此内容.临时场景被正确地取消初始化,LeakingObjectA和LeakingObjectB都出现在泄漏工具中.
class LeakingObjectA {
var strongRefToB:LeakingObjectB?
deinit{ print("LeakingObjectA deinit")}
}
class LeakingObjectB {
var strongRefToA:LeakingObjectA?
deinit{ print("LeakingObjectB deinit")}
}
class TempScene : SKScene {
let a = LeakingObjectA()
let b = LeakingObjectB()
override init() {
a.strongRefToB = b
b.strongRefToA = a
super.init(size: CGSizeZero)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
deinit {
print("Deiniting temp scene")
}
}
class ViewController {
var tempScene: TempScene?
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
tempScene = TempScene()
}
override func viewWilldisappear(animated: Bool) {
super.viewWilldisappear(animated)
tempScene = nil
}
}