swift - 如何使用 SwiftUI 交替行？

Question

当我在摆弄 SwiftUI 时，我想知道如何让水平 ScrollView 具有 2 个交替行。

我在使用示例时收到以下消息:

The compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions

import SwiftUI

struct LabelFilter: View {
    var allLabels = ["one", "two", "three", "four", "five", "six", "seven"]

    var body: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            VStack {
                HStack {
                    ForEach(allLabels.indices) { index in
                        if (index % 2 == 0) {
                            LabelButton(label: self.allLabels[index]) { }
                        }
                    }
                }.padding()
                HStack {
                    ForEach(allLabels.indices) { index in
                        if (index % 2 == 1) {
                            LabelButton(label: self.allLabels[index]) { }
                        }
                    }
                }.padding()
            }
        }
    }
}

为什么会发生这种情况，如何解决它以及是否有更好的解决方案？

Answer 1

此代码编译:

struct LabelFilter: View {
    var allLabels = ["one", "two", "three", "four", "five", "six", "seven"]

    var evenLabels: [String] {
        stride(from: 0, to: allLabels.count, by: 2).map { allLabels[$0] }
    }

    var oddLabels: [String] {
        stride(from: 1, to: allLabels.count, by: 2).map { allLabels[$0] }
    }

    var body: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            VStack {
                HStack {
                    ForEach(oddLabels, id: \.self) { label in
                        Text(label)
                    }
                }.padding()
                HStack {
                    ForEach(evenLabels, id: \.self) { label in
                        Text(label)
                    }
                }.padding()
            }
        }
    }
}