SwiftUI ForEach 'identified(by:)' 已弃用.使用 ForEach(_:id:) 或 List(_:id:) [英] SwiftUI ForEach 'identified(by:)' is deprecated. Use ForEach(_:id:) or List(_:id:)

问题描述

在 XCode 11 beta 4 上，以下内容似乎已被弃用，我不知道如何重写它.有人知道如何使用 ForEach(_:id:) 吗?

On XCode 11 beta 4 the following seems to be deprecated and I don't know how to rewrite this. Does anybody know how to use ForEach(_:id:)?

@State private var showTargets = [
    (id: 1, state: false, x: 109.28, y: 109.28),
    (id: 2, state: false, x: 683, y: 109.28),
    (id: 3, state: false, x: 1256.72, y: 109.28)
]

...

var body: some View {
    HStack {

        ForEach(showTargets.identified(by: \.id)) { item in
            Text(String(item.x))

        }
}

推荐答案

(仍在使用 Xcode 11.0/Swift 5.1)

我还没有下载 Xcode Beta 4，但根据 文档，应该是这样的:

I haven't downloaded Xcode Beta 4 yet, but according to the documentation, it should be something like:

ForEach(showTargets, id: \.id) { item in
    Text(String(item.x))
}

您还可以使用符合 Identifiable 的 struct(注意，这不适用于元组，因为您无法添加协议一致性):

You can also use a struct that conforms to Identifiable (note that this won't work on tuple because you can't add protocol conformance):

struct Targets: Identifiable {
    var id: Int
    var state: Bool
    var x: Double
    var y: Double
}

let showTargets = [
    Targets(id: 1, state: false, x: 109.28, y: 109.28),
    Targets(id: 2, state: false, x: 683, y: 109.28),
    Targets(id: 3, state: false, x: 1256.72, y: 109.28)
]

ForEach(showTargets) { item in
    Text(String(item.x))
}

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