Question

我有一个需要处理9种不同状态的表格视图。我有两个部分包含不同的数据模型（A，B）这两个部分的逻辑相互依赖

0,1

是否存在处理多个状态的标准？我正在考虑创建某种状态结构。处理此问题的“行业标准”是什么？

这是我目前正在使用的-许多计算变量

1) !A.isEmpty
2) !B.isEmpty
3) A show expandable footer (A.count > 5)
4) B show expandable footer (B.count > 5)
5) A shows collapsable footer (user clicked on A.expandable footer)
6) B shows collapsable footer (user clicked on B.expandable footer
7) A.count > 3 && B.isEmpty
8) B.count > 3 && A.isEmpty
9) A.count > 3 && B.isEmpty && A shows collapsable footer (user clicked on A.expandable footer)

Answer 1

我认为枚举或结构可以满足您的需求。

struct Video {
enum State {
    case willDownload(from: URL)
    case downloading(task: Task)
    case playing(file: File, progress: Double)
    case paused(file: File, progress: Double)
}

var state: State

}

    private func resolveActionButtonImage() -> UIImage {
    // The image for the action button is declaratively resolved
    // directly from the video state
    switch video.state {
        // We can easily discard associated values that we don't need
        // by simply omitting them
        case .willDownload:
            return .wait
        case .downloading:
            return .cancel
        case .playing:
            return .pause
        case .paused:  
            return .play
    } 
}

}

参考： https://www.swiftbysundell.com/posts/modelling-state-in-swift

Answer 2

我决定使用一个对象来保存逻辑并使用位掩码充当状态。

private struct StateModel: OptionSet {
    let rawValue: Int

    static let AIsEmpty = StateModel(rawValue: 1 << 0)
    static let AHasValues = StateModel(rawValue: 1 << 1)
    static let BIsEmpty = StateModel(rawValue: 1 << 2)
    static let BHasValues = StateModel(rawValue: 1 << 3)
    static let AFooterIsVisible = StateModel(rawValue: 1 << 4)
    static let BIsVisible = StateModel(rawValue: 1 << 5)
    static let AFooterIsExpanded = StateModel(rawValue: 1 << 6)
    static let BFooterIsExpanded = StateModel(rawValue: 1 << 7)
    static let AFooterShowsCTA: StateModel = [.AHasValues, .BIsEmpty]
    static let BFooterShowCTA: StateModel = [.AIsEmpty, .BHasValues]
    static let ACTAAsCell: StateModel = [.AFooterShowsCTA, .AFooterIsVisible]
    static let BCTAAsCell: StateModel = [.BFooterShowCTA, .BFooterIsExpanded]
}

class Logic {

var stateModel: StateModel = []

//Should AFooter show CTA?
var showAFooter: Bool {
  stateModel.contains(.AFooterShowsCTA)
}

}

快速处理多个状态

2 个答案: