Xcode 11中表达式类型不明确，没有更多上下文

Question

我尝试在中引用[Item]列表，@EnvironmentObject但是在中访问它时SwiftUI List出现错误。我不明白的是，按照Apple的Landmark教程不会弹出此错误。

据我所知，[Item]列表可以正确加载，因为我可以打印出来并执行其他功能。当将它用于A时，它只会出错。SwiftUI List是否有我遗漏的东西？

ItemHome.swift：

struct ItemHome : View {

    @EnvironmentObject var dataBank: DataBank

    var body: some View {
        List {
            ForEach(dataBank.itemList) { item in
                Text("\(item.name)") // Type of expression is ambiguous without more context
            }
        }
    }
}

支持代码如下：

物品结构：

struct Item {

    var id: Int
    var uid: String
    var company: String
    var item_class: String
    var name: String
    var stock: Int
    var average_cost: Decimal
    var otc_price: Decimal
    var dealer_price: Decimal
    var ctc_price: Decimal
}

DataBank.swift：

final class DataBank : BindableObject {
    let didChange = PassthroughSubject<DataBank, Never>()

    var itemList: [Item] = load("itemsResults.json") {
        didSet {
            didChange.send(self)
        }
    }
}

func load<T: Decodable>(_ filename: String, as type: T.Type = T.self) -> T {
let data: Data

guard let file = Bundle.main.url(forResource: filename, withExtension: nil)
    else {
        fatalError("Couldn't find \(filename) in main bundle.")
}

do {
    data = try Data(contentsOf: file)
} catch {
    fatalError("Couldn't load \(filename) from main bundle:\n\(error)")
}

do {
    let decoder = JSONDecoder()
    return try decoder.decode(T.self, from: data)
} catch {
    fatalError("Couldn't parse \(filename) as \(T.self):\n\(error)")
}

}

itemsResults.json：

[
    {
        "id": 1,
        "uid": "a019bf6c-44a2-11e9-9121-4ccc6afe39a1",
        "company": "Bioseed",
        "item_class": "Seeds",
        "name": "9909",
        "stock": 0,
        "average_cost": 0.0,
        "otc_price": 0.0,
        "dealer_price": 0.0,
        "ctc_price": 0.0
    },
    {
        "id": 2,
        "uid": "a019bf71-44a2-11e9-9121-4ccc6afe39a1",
        "company": "Pioneer",
        "item_class": "Seeds",
        "name": "4124YR",
        "stock": 0,
        "average_cost": 0.0,
        "otc_price": 0.0,
        "dealer_price": 0.0,
        "ctc_price": 0.0
    }
]

Answer 1

显然我错过了确保我的模型（Item在这种情况下）符合Identifiable协议修复它。不过，我希望 Apple 能够更清楚地了解他们的错误消息。

Answer 2

正如您在回答中提到的， aForEach需要一个Identifiable对象列表。但是，如果您不想让您的对象实现该协议（或由于某种原因不能），那么这里有一个技巧：

item.identifiedBy(\.self)