如何使用一个变量/属性而不是分配相同的属性三次?

Question

让我们假设myVar在每个视图实现中都具有相同的功能。我试图弄清楚如何声明/公开某种仅设置属性，而不是将它们分配 n 次(创建每个新视图(，但我没有任何想法。如何重构为一行和一次性分配？

var myVar: (()-> Void)?
private func callBack() {
someClass.view1.myVar = self.myVar
someClass.view2.myVar = self.myVar
someClass.view3.myVar = self.myVar
}
// MARK: - someClass pseudocode
someClass: class {
let view1: CustomView: = CustomView
let view2: CustomView: = CustomView
let view3: CustomView: = CustomView
}
// MARK: - customView pseudocode
class CustomView: UIView {
var myVar: (()-> Void)?
}

Answer 1

类似的东西，但是将所有CustomViews放在数组中是个好主意，也可以在这里实现

var a: (() -> Void)?
class CustomView: UIView {
var myVar: (() -> Void)?
}
class SomeClass {
let view1 = CustomView()
let view2 = CustomView()
let view3 = CustomView()
var myVar: (() -> Void)? {
set {
self.view2.myVar = newValue
self.view1.myVar = newValue
self.view3.myVar = newValue
}
get {
return self.myVar
}
}
}
let b = SomeClass()
b.myVar = ({print(3)})
b.view1.myVar!()

Answer 2

这是你想做的吗？

[someClass.view1, someClass.view2, someClass.view3].forEach { $0.myVar = self.myVar }

Answer 3

这就是我处理这些问题的方式：

class OtherClass {
var text: String?
init(text: String?) {
self.text = text;
}
}
class TestClass {
var thing1: OtherClass?
var thing2: OtherClass?
var thing3: OtherClass?

var allTheThings: [OtherClass?] { return [thing1, thing2, thing3]}
var ownText: String? {
didSet {
allTheThings.forEach { $0?.text = ownText }
}
}
}

根据你期望事情变化的程度，你可以使数组属性成为你在 init 中设置的常量，而不是计算属性。

如果你想变得花哨，你也可以做这样的事情来设置：

private var allTheThings: [OtherClass?] {
get {
return [thing1, thing2, thing3]
}
set {
guard newValue.count == 3 else {
//probably should put an assertion in here
return
}
thing1 = newValue[0]
thing2 = newValue[1]
thing3 = newValue[2]
}
}
init() {
self.allTheThings = Array(repeating: OtherClass(text: "Test"), count: 3)
}