[核心数据]：数据：<fault>

Question

函数中的questions参数已满，但我不能将赋值传递给questionsCD.questions?.questionList。

id 和 title 变量是 not nil**.这些变量正在健康地工作。**

在控制台输出中，questions返回nil。

我无法在questionList QuestionsNSSecureCoding 类中分配变量，因此我认为它返回零。为什么?

您可以检查核心数据实体映像，以更详细地查看questionsCD.questions?.questionList。

​

​

核心数据保存功能：

func saveSelectedQuestion(questionTitle: String, id: String, questions: [QuestionList]) {
    
    let questionsCD = QuestionCD(context: persistentContainer.viewContext)
    questionsCD.title = questionTitle
    questionsCD.id = id
    questionsCD.questions?.questionList = questions
    print("nil test: \(questionsCD.questions?.questionList ?? [])")
    
    do {
        try persistentContainer.viewContext.save()
    } catch let error {
        print("Failed to save selected category: \(error.localizedDescription)")
    }
}

核心数据获取函数：

func getSelectedQuestion(questionID: String) -> [QuestionCD] {
    let fetchRequest: NSFetchRequest<QuestionCD> = QuestionCD.fetchRequest()
    let search = NSPredicate(format: "id == %@", questionID)
    print("search: \(search)")
    fetchRequest.predicate = search
    fetchRequest.returnsObjectsAsFaults = false
    print("request predicate: \(String(describing: fetchRequest.predicate))")
    do {
        return try persistentContainer.viewContext.fetch(fetchRequest)
    } catch let error {
        print("get hata: \(error.localizedDescription)")
        return []
    }
}

控制台输出：

selectedQuestionCD [<QuestionCD: 0x2800e8e60> (entity: QuestionCD; id: 0x9d00d28ec7359eb0 <x-coredata://089E80AC-0E4F-4303-BF8F-47C31EC70ED4/QuestionCD/p2>; data: {
    id = "agustos_test_1";
    questions = nil;
    title = "A\U011fustos Test 1";
})]

核心数据实体：

​

​

问题NSSecure编码：

public class QuestionsNSSecureCoding: NSObject, NSSecureCoding {
    
    public static var supportsSecureCoding: Bool = true
    
    var questionList: [QuestionList]

    
    required init(questions: [QuestionList]) {
        self.questionList = questions

    }
    
    public func encode(with coder: NSCoder) {
        coder.encode(questionList, forKey: "questionList")

    }
    
    required public init?(coder: NSCoder) {
        
        questionList = coder.decodeObject(of: NSArray.self, forKey: "questionList") as? Array<QuestionList> ?? []

    }
}

问题值转换器：

@objc(QuestionsValueTransformer)
final class QuestionsValueTransformer: NSSecureUnarchiveFromDataTransformer {
    static let name = NSValueTransformerName(rawValue: String(describing: QuestionsValueTransformer.self))
 
    override static var allowedTopLevelClasses: [AnyClass] {
        return [QuestionsNSSecureCoding.self]
    }
    
    public static func register() {
            let transformer = QuestionsValueTransformer()
            ValueTransformer.setValueTransformer(transformer, forName: name)
        }
}

我的自定义模型：

class QuestionContainer: Codable {
    
    var questionCategories: [Question]
    
    init(questionCategories: [Question]) {
        self.questionCategories = questionCategories
    }
}

class Question: Codable, Identifiable {
    
    var title: String
    var id: String
    var questions: [QuestionList]
    
        init(title: String, id: String, questions: [QuestionList]) {
            self.title = title
            self.id = id
            self.questions = questions
        }
}

class QuestionList: Codable, Identifiable {
    
    var id: String
    
    init(id: String) {
        self.id = id
    } 
}

Answer 1

我认为问题是questionCD.questions是零，所以这条线

questionsCD.questions?.questionList = questions

什么都不做。您需要使用正确的问题数组创建一个QuestionsNSSecureCoding实例，并将其分配给questions属性：

questionsCD.questions = QuestionsNSSecureCoding(questions: questions)