我有一个采用ObservableObject协议的activity类，并具有一个items数组属性，该属性存储也采用ObservableObject的activity对象。

class activity: ObservableObject,Codable,Identifiable {
    let id = UUID()
    @Published var title: String
    @Published var description: String
    @Published var numberOfTimesCompleted: Int = 0

    func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: CodingKeys.self)

        try container.encode(title,forKey: .title)
        try container.encode(description,forKey: .description)
        try container.encode(numberOfTimesCompleted,forKey: .numberOfTimesCompleted)
    }

    init(title: String,description: String) {
        self.title = title
        self.description = description
        numberOfTimesCompleted = 0
    }

    required init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)

        title = try container.decode(String.self,forKey: .title)
        description = try container.decode(String.self,forKey: .description)
        numberOfTimesCompleted = try container.decode(Int.self,forKey: .numberOfTimesCompleted)
    }
}

class activities: ObservableObject {
    @Published var items: [activity] {
        didSet {
            let encoder = JSONEncoder()
            if let encoded = try? encoder.encode(items) {
                UserDefaults.standard.set(encoded,forKey: "items")
            }
        }
    }

    init() {
        if let items = UserDefaults.standard.data(forKey: "items") {
            let decoder = JSONDecoder()
            if let decoded = try? decoder.decode([activity].self,from: items) {
                self.items = decoded
                return
            }
        }

        self.items = []
    }
}

我正在使用List这样动态显示我的数组

List {
  ForEach(activities.items) { activity in
    NavigationLink(destination: activityView(activity: activity)) {
      HStack {
        Text("\(activity.numberOfTimesCompleted)")
        VStack(alignment: .leading) {
          Text(activity.title)
          Text(activity.description)
        }
      }
    }
  }
}

当我将“活动”传递到另一个视图（在NavigationLink中）并编辑numberOfTimesCompleted属性时，当我导航回到列表时，更改不会反映出来。如果将新的activity实例添加到列表中，列表将更新，并且新的numberOfTimesCompleted值会反映在我之前编辑的activity中。我有一种接近的感觉，但是我正在学习Swift和ObservableObject，因此缺少一些东西。