我正在探索内存管理概念,并发现deinit
方法不是在Xcode 10 beta 6操场中调用。最初我认为可能是代码中的一些问题。然后我在Xcode 9.4.1 playground和Xcode 10 beta 6示例应用程序中测试相同的代码,一切都按预期工作(deinit方法被调用)。它是Xcode 10 beta 6游乐场或其他任何东西的错误吗?我正在使用苹果开发者的代码 -
class Person {
let name: String
weak var apartment: Apartment?
init(name: String) {
self.name = name
print("\(name) is being initialized")
}
deinit { print("\(name) is being deinitialized") }
}
class Apartment {
let unit: String
weak var tenant: Person?
init(unit: String) { self.unit = unit
print("Apartment \(unit) is being initialized")
}
deinit { print("Apartment \(unit) is being deinitialized") }
}
do {
var john: Person?
var unit4A: Apartment?
john = Person(name: "John Appleseed")
unit4A = Apartment(unit: "4A")
john!.apartment = unit4A
unit4A!.tenant = john
john = nil
unit4A = nil
}
这个问题似乎仍然出现在Xcode 10.0(10A255)中。我有一个带有以下代码的游乐场:
class Person {
var name: String
func buy(car: Car) {
car.owner = self
}
init(name: String) {
self.name = name
print("Person \(name) is initalized")
}
deinit {
print("Person \(name) is being deinitialized")
}
}
class Car {
let model: String
weak var owner: Person?
init(model: String) {
self.model = model
print("Car \(model) is initialized")
}
deinit {
print("Car \(model) is being deinitialized")
}
}
print("===== before do =====")
do {
print(" ---- do begin -----")
let johnny = Person(name: "John")
let porsche = Car(model: "Carrera4")
johnny.buy(car: porsche)
print(" ---- do end -----")
}
print("===== after do =====")
在Xcode 9.4.1中,Car和Person的deinit都被执行,但是在Xcode 10.0(10A255)中,Person的deinit方法没有被执行。
测试macOS项目中的相同代码在Xcode 9.4.1以及Xcode 10.0(10A255)中按预期工作(两者都是deinit执行)