初始化需要“自我”的Swift属性作为一个论点 [英] Initializing Swift properties that require "self" as an argument

问题描述

我有一个Swift类，我希望看起来像这样：

I have a Swift class that I'd like to look something like this:

class UpdateManager {
  let timer: NSTimer

  init() {
    timer = NSTimer(timeInterval: 600, target: self, selector: "check", userInfo: nil, repeats: true)
  }

  func check() {
    // Do some stuff
  }
}

但是，Swift不喜欢我将 self 传递给 NSTimer 初始化程序。我在这里打破了一些模式吗？一个人应该如何完成这样的初始化？

However, Swift doesn't like the fact that I'm passing self to the NSTimer initializer. Am I breaking some pattern here? How is one supposed to accomplish initialization like this?

推荐答案

你找到了隐式展开可选。

• 您需要从 self > init ，在初始化 timer 之前。


• 否则， timer 永远不会为零，所以你不必在 init 之外检查它。

• You need to access self from init, before timer is initialized.
• Otherwise, timer should never be nil, so you shouldn't have to check it outside of init.

所以，你应该声明让计时器：NSTimer！。

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