ios - swift 中的多个枚举值

Question

我想创建一个像这样的枚举值

view.autoresizingMask = [UIViewAutoresizing.FlexibleBottomMargin, UIViewAutoresizing.FlexibleHeight]

我不知道如何设计 enum 来接受多个变量。

我想设计以下内容。

enum ActivityType: Int {
    case Event = 1
    case CommentOnEvent = 2
    case CommentOnComment = 3
}
var activityType = [CommentOnEvent, CommentOnComment]

var activityType = Event

Answer 1

它不是一个enum，它是一个符合OptionSetType 的struct。您可以按照以下模式创建一个:

struct AnimalTraits : OptionSetType {
    let rawValue: Int
    init(rawValue: Int) { self.rawValue = rawValue }

    static let LaysEggs = AnimalTraits(rawValue: 1)
    static let GivesLiveBirth = AnimalTraits(rawValue: 2)
    static let HasFur = AnimalTraits(rawValue: 4)
    static let HasScales = AnimalTraits(rawValue: 8)

    static let Mammal: AnimalTraits = [GivesLiveBirth, HasFur]
    static let Fish: AnimalTraits = [LaysEggs, HasScales]
}

然后你可以像这样使用它:

struct Animal {
    let name: String
    let traits: AnimalTraits
}

let salmon = Animal(name: "Salmon", traits: .Fish)

salmon.traits.contains(.HasFur) //false
salmon.traits.contains(.HasScales) //true

let bizarro = Animal(name: "Fictional Animal", traits: [.LaysEggs, .GivesLiveBirth])