arrays - 如何在 Swift 中对具有关联值的枚举数组进行排序？

Question

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我有一组具有关联值的枚举，我想按时间顺序对其进行排序。其中一个值包含一个日期(作为字符串)，该日期将被显示并应用于排序。

这是目前的样子:

enum cellType {
    case standard(text: String, icon: UIImage, hasChildren: Bool, reference: String)
    case detailed(text: String, secondaryText: String, icon: UIImage, hasChildren: Bool, reference: String)

    var identifier: String {
        switch self {
        case .standard: return "standardCell"
        case .detailed: return "detailedCell"
        }
    }
}

var cellData: [cellType]

然后 cellData 会填充一些 cellType。 secondaryText 的值包含日期，如下所示:

print(cellData) 

// [
//    AppIdentifier.cellType.detailed(text: "Title A", secondaryText: "2017-10-20T10:04:00.000+02:00", icon: <UIImage: 0x60c0002a6660>, {12, 21}, hasChildren: false, reference: "40693"),
//    AppIdentifier.cellType.detailed(text: "Title B", secondaryText: "2016-12-14T10:04:00.000+02:00", icon: <UIImage: 0x60c0002a6660>, {12, 21}, hasChildren: false, reference: "40632")
//    AppIdentifier.cellType.detailed(text: "Title C", secondaryText: "2017-10-20T10:07:00.000+02:00", icon: <UIImage: 0x60c0002a6660>, {12, 21}, hasChildren: false, reference: "40694"),
//    AppIdentifier.cellType.detailed(text: "Title D", secondaryText: "2017-11-16T10:34:00.000+02:00", icon: <UIImage: 0x60c0002a6660>, {12, 21}, hasChildren: false, reference: "40633"),
//    AppIdentifier.cellType.detailed(text: "Title E", secondaryText: "2017-10-19T10:12:00.000+02:00", icon: <UIImage: 0x60c0002a6660>, {12, 21}, hasChildren: false, reference: "40682"),
// ]

当我尝试对数组进行排序时，下面的代码显然太简单了:

var cellDataSorted = cellData.sorted(by: {$0.detailed.secondaryText < $1.detailed.secondaryText})

// Swift Compiler Error: enum element ’detailed’ cannot be referenced as an instance member

对这个数组进行排序的最佳方法是什么？提前致谢!

Answer 1

(我是在手机上写的，所以..如有必要请修正语法)

在排序函数中使用以下代码:

if case .detailed(_, let date0, _, _, _) = $0, case .detailed(_, let date1, _, _, _) = $1 {
     return date0 < date1
} else {
    // One of them didn't have date (should never happen)
    return true
}

您的问题是，您正在访问枚举的参数，就好像它是类/结构的实例一样。