如何制作一个闭包以符合“AccessibilityRotorContent”？

Question

我创建了一个显示一堆卡片的视图。我向它传递两个参数：

• 卡片数据数组
• 为每张卡片构建 CardView 的闭包：

struct CardStack: View {
    var cards: [Card]
    var content: (Int, Card) -> CardView

    init(cards: [Card], @ViewBuilder content: @escaping (Int, Card) -> CardView) {
        self.cards = cards
        self.content = content
    }
    
    var body: some View {
        ZStack {
            ForEach(Array(cards.enumerated()), id: \.element.id) { index, card in
                content(index, card)
            }
        }
    }
}

当闭包仅包含 CardView 时，它工作得很好，但是一旦我向 CardView 添加任何视图修饰符（并且我需要添加其中的许多视图修饰符），闭包的返回类型就会更改为

some View

，并且我得到错误：

Cannot convert return expression of type 'some View' to return type 'CardView'

var deckBody: some View {
    CardStack(cards: viewModel.cards) { index, card in  // Error: Cannot convert return expression of type 'some View' to return type 'CardView'
        CardView(card: card)
            .zIndex(Double(index))
    }
}

然后，当我修改 CardView 以期望闭包返回

any View

而不是

CardView

时，我收到另一个错误

Static method 'buildExpression' requires that 'Content' conform to 'AccessibilityRotorContent'

：

struct CardStack: View {
    var cards: [Card]
    var content: (Int, Card) -> any View

    init(cards: [Card], @ViewBuilder content: @escaping (Int, Card) -> any View) {
        self.cards = cards
        self.content = content
    }
    
    var body: some View {
        ZStack {
            ForEach(Array(cards.enumerated()), id: \.element.id) { index, card in
                content(index, card)     // Error: Static method 'buildExpression' requires that 'Content' conform to 'AccessibilityRotorContent'
            }
        }
    }
}

我为什么要这样做，以及如何使闭包符合“AccessibilityRotorContent”？

Answer 1

CardStack

应该有一个通用类型参数，指示每张卡片显示的

View

的类型。

struct CardStack<CardContent: View>: View {
    var cards: [Card]
    var content: (Int, Card) -> CardContent

    init(cards: [Card], @ViewBuilder content: @escaping (Int, Card) -> CardContent) {
        self.cards = cards
        self.content = content
    }

    ...
}