Swift 自我功能保留弱

Question

如果我有一个引用 weak var weakSelf = self 的闭包，我可以通过 weakSelf 将该闭包更改为直接函数引用吗？

struct ClosureHolder {
    let closure: () -> Void
}

class ClosureSource {
    func hello() {
        NSLog("hello")
    }

    func createWeakSelfWithinInnerClosureClosureHolder() -> ClosureHolder {
        weak var weakSelf = self
        return ClosureHolder(closure: {
            weakSelf?.hello()
        })
    }

    func createWeakSelfDotHelloClosureHolder() -> ClosureHolder {
        weak var weakSelf = self
        // The code below won't compile because weakSelf is an Optional.
        // Once I unwrap the optional, I no longer have a weak reference.
        // return ClosureHolder(closure: weakSelf.hello)

        // this strongifies the weak reference. :(
        return ClosureHolder(closure: weakSelf!.hello)
    }
}

而不是 createWeakSelfWithinInnerClosureClosureHolder，我更喜欢 createWeakSelfDotHelloClosureHolder。

Answer 1

不，你不能。说 self.foo（如果 foo 是一个方法）和说 MyClass.foo(self) 完全一样。以这种方式柯里化的方法总是保持对接收者对象的强引用。如果你想保持弱引用，那么你需要坚持使用 { weakSelf?.hello() } 方法。

Swift 自我功能保留弱

Swift weak self function retention

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