[SwiftUI]：ForEach 不适用于字典数组、带数组的字典

Question

我尝试在 SwiftUI 中遍历数组，但它不能正常工作。

我的代码：

let arr_type2  = [
                    ["type":"Temperature","Units":["°C","°F","°K"]],
                    ["type":"Length","Units":["m","km","ft","yd","mi"]],
                    ["type":"Time","Units":["sec","min","hr","day"]],
                    ["type":"Volume","Units":["ml","lt","cups","pints","gallons"]]
                    ]

ForEach(arr_type2, id: \.self) { dict in //Error
        Text("")
}

错误：协议类型“Any”不能符合“Hashable”，因为只有具体类型才能符合协议

我刚开始学习 SwiftUI，你能帮我保存一下吗？

感谢您宝贵的时间！

Answer 1

你可以干净利落地写出来

struct Model:Hashable {
    let type:String
    let unnits:[String]
}

struct ContentView: View {

    let arr_type2 = [Model(type:"Temperature", unnits: ["°C","°F","°K"])]

    var body: some View {
           ForEach(arr_type2, id: \.self) { item in

            Text(item.type)
        }
    }
}

为什么检查https://www.hackingwithswift.com/books/ios-swiftui/why-does-self-work-for-foreach

Answer 2

你可以像这样使用ForEach

 var body: some View {
    let arr_type2  = [
        ["type":"Temperature","Units":["°C","°F","°K"]],
        ["type":"Length","Units":["m","km","ft","yd","mi"]],
        ["type":"Time","Units":["sec","min","hr","day"]],
        ["type":"Volume","Units":["ml","lt","cups","pints","gallons"]]
    ]

    return ForEach(0..<arr_type2.count, id: \.self) { index -> AnyView in
        let units = arr_type2[index]["Units"] as! [String]
        return AnyView(VStack {
            Text(arr_type2[index]["type"] as! String)
            ForEach(0..<units.count, id: \.self) { indexUnits in
                 Text(units[indexUnits])
            }

        })
    }

}