swift json：用户默认值中的一个键 - 两个结构

Question

我想使用一个密钥将数据保存到UserDefaults。然后我们检查 - 如果输入是'Task'然后在TableViewCell中写入Do;如果'Project'然后让用户移动到另一个TableViewController以查看所有任务。请帮助编码/解码...

protocol UserEntry: Codable {}

struct Task: UserEntry, Codable {
    var toDo: String
}

struct Project: UserEntry, Codable {
    var name: String
    var tasks: [Task]
}

var userEntries: [UserEntry] {
    get {
        guard let encodedData = UserDefaults.standard.data(forKey: "userEntry"), let decodedData = try? JSONDecoder().decode([UserEntry].self, from: encodedData) else { return [] }
        return decodedData
    }
    set {
        guard let encodedData = try? JSONEncoder().encode(newValue) else { return }
        UserDefaults.standard.set(encodedData, forKey: "userEntry")
    }
}

userEntries.append(Task(toDo: "write a letter"))
userEntries.append(Project(name: "Make a dinner", tasks: [Task(toDo: "buy food"), Task(toDo: "cook food")]))