SwiftUI:为什么 ForEach($strings) (text: Binding<String>) 不构建? [英] SwiftUI: Why does ForEach($strings) (text: Binding&lt;String&gt;) not build?

问题描述

我有一个 ForEach 它接受一个 Binding<[String]> 并且它用 Xcode11 beta5 编译得很好，但是用 beta6 它说表达式类型不明确，没有更多上下文在 ForEach 内的 Text("...") 上，我找不到错误.是不是我不能再迭代这样的绑定了?

I have a ForEach which takes a Binding<[String]> and it compiled with Xcode11 beta5 fine but with beta6 it says Type of expression is ambiguous without more context on the Text("...") inside the ForEach and I can't find the mistake. Is it that I can't iterate over such a binding anymore?

struct ForEachItem1: View {
    @Binding var items: [String]
    var body: some View {
        ForEach($items) { item in
            Text("Hello world") // Type of expression is ambiguous without more context
        }
    }
}

struct ForEachItem2: View {
    @Binding var items: [String]
    var body: some View {
        ForEach($items) { (item: Binding<String>) in
            Text("Hello world") // Type of expression is ambiguous without more context
        }
    }
}

推荐答案

Binding 到 Collection 的条件一致性已被删除(有关弃用通知，请参阅 Xcode11 Beta5 发行说明).在以后的发行说明/版本中找不到.

The conditional conformance of Binding to Collection was removed (see Xcode11 Beta5 Release Notes for deprecation notice). It can't be found in later release notes/releases.

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