無法使用SwiftUI將JSON（嵌套字典）決議為ForEach

我想用 SwiftUI 將以下 JSON 決議成一個串列，但是我遇到了一些問題。

JSON（以隨機識別符號作為條目的整體比這多得多。這就是導致它更難執行的原因）：

{
  "DCqkboGRytms": {
    "name": "graffiti-brush-3.zip",
    "downloads": "5",
    "views": "9",
    "sha256": "767427c70401d43da30bc6d148412c31a13babacda27caf4ceca490813ccd42e"
  },
  "gIisYkxYSzO3": {
    "name": "twitch.png",
    "downloads": "19",
    "views": "173",
    "sha256": "aa2a86e7f8f5056428d810feb7b6de107adefb4bf1d71a4ce28897792582b75f"
  },
  "bcfa82": {
    "name": "PPSSPP.ipa",
    "downloads": "7",
    "views": "14",
    "sha256": "f8b752adf21be6c79dae5b80f5b6176f383b130438e81b49c54af8926bce47fe"
  }
}

SwiftUI 可編碼：

struct Feed: Codable {
    let list: [FeedValue]
}

struct FeedValue: Codable, Identifiable {
    var id = UUID()
    let name, downloads, views, sha256: String
}

JSON Fetch 方法（和決議）：

func getFeeds(completion:@escaping (Feed) -> ()) {

    // URL hidden to respect API privacy
    
    guard let url = URL(string: "") else { return }
    URLSession.shared.dataTask(with: url) { (data, _, _) in
        
        let feed = try! JSONDecoder().decode(Feed.self, from: data!)
        
        DispatchQueue.main.async {
            completion(feed)
        }
        
    }.resume()
    
}

最后，包含我的 ForEach 回圈的視圖：

struct HomeView: View {
    
    @State private var scrollViewContentOffset: CGFloat = .zero
    
    @State var listFeed = Feed(list: [])
    
    var body: some View {
        
        // Z-coord status bar holder
        ZStack(alignment: .top) {
            TrackableScrollView(.vertical, showIndicators: true, contentOffset: $scrollViewContentOffset) {
                
                
                // Public files Start
                LazyVStack(spacing: 0) { {
                    // Withholds our content for each asset retrieved.

                    // Main part
                    ForEach(listFeed.list, id: \.id) { download in
                        AssetView(name: .constant(download.name), downloads: .constant(download.downloads), views: .constant(download.views))
                    }

                }.padding([.leading, .top, .trailing], 25)
                // Public files End
                
            }.edgesIgnoringSafeArea([.leading, .trailing, .top])
            
        }.background(Color.backgroundColor.ignoresSafeArea())
            .onAppear() {
                getFeeds { feed in
                    //print(feed) : this did happen to work at the time of testing
                    self.listFeed = feed
                }
            }
        
    }
}

對于出現的錯誤：

Starfiles/HomeView.swift:32：致命錯誤：“嘗試！” 運算式意外引發錯誤：Swift.DecodingError.keyNotFound(CodingKeys(stringValue: "list", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with key CodingKeys(stringValue: "list ", intValue: nil) ("list").", 基礎錯誤: nil))

我今天花了幾個小時更改決議方法，但無法自己找到解決方案。

編輯 1：我想提一下，我還需要一種訪問字典 ID 的方法，因為它們將用于輸入新視圖。

編輯 2：使用 @jnpdx 提供的內容，JSON 決議現在可以按預期作業，并獲得我需要的資訊。但是，ForEach 回圈存在問題，與之前一直存在的回圈相同（正如他的回答所示，它確實在 List() 中作業）。

這是更新的代碼（不會顯示任何不相關的代碼）

                    ForEach(listItems) { item in // Cannot convert value of type '[IdentifiableFeedValue]' to expected argument type 'Binding<C>' &  Generic parameter 'C' could not be inferred
                        AssetView(name: .constant(item.feedValue.name), // Cannot convert value of type 'Binding<Subject>' to expected argument type 'String'
    downloads: .constant(item.feedValue.downloads), views: .constant(item.feedValue.views))
                    }.onAppear() {
                        // URL hidden to respect API privacy, refer to JSON above.
                        guard let url = URL(string: "") else { return }
                        URLSession.shared.dataTask(with: url) { (data, _, _) in
                            
                            do {
                                list = try JSONDecoder().decode([String:FeedValue].self, from: data!)
                            } catch {
                                print("error")
                            }
                            
                        }.resume()
                    }

// AssetView
struct AssetView: View {
    
    @Binding var name: String
    @Binding var downloads: String
    @Binding var views: String

...

}

uj5u.com熱心網友回復：

您的 JSON 沒有任何名為 的鍵list，這就是它失敗的原因。因為它是一個動態鍵控字典，所以您需要將其解碼為[String:FeedValue].

我使用了一個包裝器來保留id原始 JSON，但如果你想將它保持在一個級別struct，你也可以做一些更高級的解碼，但這超出了這個問題的范圍。

let jsonData = """
{
  "DCqkboGRytms": {
    "name": "graffiti-brush-3.zip",
    "downloads": "5",
    "views": "9",
    "sha256": "767427c70401d43da30bc6d148412c31a13babacda27caf4ceca490813ccd42e"
  },
  "gIisYkxYSzO3": {
    "name": "twitch.png",
    "downloads": "19",
    "views": "173",
    "sha256": "aa2a86e7f8f5056428d810feb7b6de107adefb4bf1d71a4ce28897792582b75f"
  },
  "bcfa82": {
    "name": "PPSSPP.ipa",
    "downloads": "7",
    "views": "14",
    "sha256": "f8b752adf21be6c79dae5b80f5b6176f383b130438e81b49c54af8926bce47fe"
  }
}
""".data(using: .utf8)!

struct FeedValue: Codable {
    let name, downloads, views, sha256: String
}

struct IdentifiableFeedValue : Identifiable {
    let id: String
    let feedValue: FeedValue
}

struct ContentView: View {
    @State var list : [String:FeedValue] = [:]
    
    var listItems: [IdentifiableFeedValue] {
        list.map { IdentifiableFeedValue(id: $0.key, feedValue: $0.value) }
    }
    
    var body: some View {
        List(listItems) { item in
            Text(item.feedValue.name)
        }.onAppear {
            do {
                list = try JSONDecoder().decode([String:FeedValue].self, from: jsonData)
            } catch {
                print(error)
            }
        }
    }
}

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