问题描述
class MyClass {
func greeting() {
answer += "Hello,World!"
}
}
class Handler {
var closure: (() -> Void)?
let obj = MyClass()
func setupClosure() {
closure = {
self.obj.greeting()
}
}
deinit {
answer += "Handler is being deinitialized."
}
}
var answer: String = ""
func handlerDeinitialization() -> String {
var handler: Handler? = Handler()
handler!.setupClosure()
handler!.closure!()
handler = nil
return answer
}
print(handlerDeinitialization())
我的预期答案是“Hellow,World!Handler 正在被取消初始化。”如何解决这个问题?我只想更改一行代码,而不是整行。
解决方法
重写:
closure = { [weak self] in
if let self = self {
self.obj.greeting()
}
}
(请注意,我更改了不止一行。但我的回答是有关如何通过更改一行来完成此操作的重要线索。)