＆QUOT;实例成员不能在类型和QUOT使用;错误懒财产 [英] "Instance member cannot be used on type" error in lazy property

问题描述

请帮我解决这个问题，或者告诉我正确的方式来宣告这个属性。

  // MARK：属性
VAR expensiveItems = [项目]（）
VAR cheapItems = [项目]（）懒惰的VAR allItems：[项目]] = {
    返回[cheapItems，expensiveItems]
}（）
 

解决方案

由于你分配一个封闭的延迟加载属性的结果 - 你需要遵循封规则。其中的一个规则是，如果你指的是自 - 你必须明确地做到这一点。 <子>（虽然这并不适用于 @noescape 关闭 - 但你不能在这里反正使用它们）

这仅仅是让你承认你捕捉并保留自，但看到它是一个松散加载的属性不应该引起保留周期，它只是调用一次，它的结果，然后分配给属性。

因此​​，你需要使用 self.cheapItems 和 self.expensiveItems 。

  // MARK：属性
VAR expensiveItems = [项目]（）
VAR cheapItems = [项目]（）懒惰的VAR allItems：[项目]] = {
    返回[self.cheapItems，self.expensiveItems]
}（）
 

Please help me solve this problem or tell me the right way to declaring this property.

// MARK: Properties
var expensiveItems = [Item]()
var cheapItems = [Item]()

lazy var allItems: [[Item]] = {
    return [cheapItems, expensiveItems]
}()

解决方案

Because you're assigning the result of a closure to your lazily loaded property - you need to follow the closure rules. One of those rules is that if you're referring to self - you must do it explicitly. _{(although this isn't applicable for @noescape closures – but you can't use them here anyway)}

This is simply so that you acknowledge that you're capturing and retaining self, but seeing as it's a lazily loaded property it shouldn't cause a retain cycle, as it is only called once and it's result is then assigned to the property.

Therefore you need to use self.cheapItems and self.expensiveItems.

// MARK: Properties
var expensiveItems = [Item]()
var cheapItems = [Item]()

lazy var allItems: [[Item]] = {
    return [self.cheapItems, self.expensiveItems]
}()

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