在SwiftUI中使用JSON解码时如何解决此问题？

Question

我是学习Swift和SwiftUI的初学者。我想学习如何使用API​​和解码JSON。我在YouTube上找到了tutorial。它与视频中显示的iTunes API一起使用。然后，我将其替换为API about the Coronavirus。不幸的是，此后它始终在控制台中显示“获取失败：未知错误”。

[谁能帮我解决这个问题？谢谢！

而且任何人都可以告诉我，如何在单独的Text（而不是列表！）中显示该JSON文件的特定值！再次感谢！

这是代码：

import SwiftUI

struct Response: Codable {
    var countries: [Result]
}

struct Result: Codable {
    let id = UUID()
    var Country: String
    var TotalConfirmed: Int
    var TotalDeaths: Int
}

struct ExampleCorona: View {
    @State private var countries = [Result]()

    var body: some View {
        List(countries, id: \.id) { item in
            VStack(alignment: .leading) {
                Text(item.Country)
                    .font(.headline)
                Text("\(item.TotalConfirmed)")
            }
        }.onAppear(perform: loadData)
    }

    func loadData() {
        guard let url = URL(string: "https://api.covid19api.com/summary") else {
            print("Invalid URL")
            return
        }

        let request = URLRequest(url: url)

        URLSession.shared.dataTask(with: request) { data, response, error in
            if let data = data {
                if let decodedResponse = try? JSONDecoder().decode(Response.self, from: data) {
                    // we have good data – go back to the main thread
                    DispatchQueue.main.async {
                        // update our UI
                        self.countries = decodedResponse.countries
                    }

                    // everything is good, so we can exit
                    return
                }
            }

            // if we're still here it means there was a problem
            print("Fetch failed: \(error?.localizedDescription ?? "Unknown error")")
        }.resume()
    }
}

Answer 1

如果JSON密钥的数量不等于您必须指定CodingKeys的结构成员的数量，则您要解码的那些密钥

struct Result: Codable {
   let id = UUID()
   let country : String
   let totalConfirmed : Int
   let totalDeaths : Int

   private enum CodingKeys: String, CodingKey { 
       case country = "Country" 
       case totalConfirmed = "TotalConfirmed" 
       case totalDeaths = "TotalDeaths"
   }
}