foreach - 如何在例如分配变量SwiftUI 中的 ForEach？

Question

是否可以在 SwiftUI 中设置变量，例如在这样的 ForEach 中:

struct ContentView: View {
    var test: Int

    var body: some View {

        List {
            ForEach(1...5, id: \.self) {
                Text("\($0)…")

                test = $0 // how to realise this?
            }
        }

    }
}

我无法让它生效，我收到如下错误:

Unable to infer complex closure return type; add explicit type to disambiguate

Answer 1

您不能分配给 test来自您内部任何地方的任何东西 ContentView ，因为它是结构体，所以，self是不可变的，但您将能够执行以下操作:

struct ContentView: View {
//    var test: Int // cannot be assigned, because self is immutable

    var body: some View {
        List {
            ForEach(1...5, id: \.self) { (i) -> Text in
                let test = i // calculate something intermediate
                return Text("\(test)…")
            }
        }
    }
}