ios - 如何将数据从iOS中的数据模型存储到核心数据中，并以数据模型的格式获取

Question

我想在 iOS 中将数据存储为数据模型。 我正在尝试这个，但它不起作用。

我的数据模型类

class FileSaveModel: NSManagedObject {
    @NSManaged var id: String
    @NSManaged var name: String
    @NSManaged var path: String
    @NSManaged var time: String
    @NSManaged var type: String
    @NSManaged var uid: String

    // TODO: - Need to get the use of this
   // lazy var uidd: NSManagedObjectID = NSManagedObjectID()

    override init(entity: NSEntityDescription, insertInto context: NSManagedObjectContext?) {
        super.init(entity: entity, insertInto: context)
    }

    init(name:String, path: String, contentType: ContentType, entity: NSEntityDescription, insertInto context: NSManagedObjectContext?) {
        super.init(entity: entity, insertInto: context)

        self.path = path
        self.name = name
        self.type = contentType.rawValue
        self.time = "\(NSDate())"
        self.uid = "56"
        self.id = "789"
    }
}

这样保存

func save(name: String, path: String, type: ContentType, modelContent: ModelTest)  {

        guard let entity = self.entityWith(name: entityName) else {
            return
        }

当我尝试用它保存时，它保存了

//let modelFile = FileSaveModel(name: name, path: path, contentType: //type, entity: entity, insertInto: appDelegate.context())

但这会导致错误“无法将 NSManagedObject 转换为 FileSaveModel”

        let model = NSEntityDescription.insertNewObject(forEntityName: entityName, into: appDelegate.context()) as! FileSaveModel

        model.name = name
        model.path = path
        model.type = type.rawValue

        save(model: model, modelContent: modelContent)
    }

    func save(model: FileSaveModel, modelContent: ModelTest) {

        do {
            try appDelegate.context().save()
            print("Save successful")
        } catch {
            fatalError("Failure to save context: \(error)")
        }
    }

像这样获取数据但不返回 FileSaveModel 数组只返回 NSManagedObject 数组

func fetchAllModels() {
        let fetchItems = NSFetchRequest<NSFetchRequestResult>(entityName: entityName)

        do {

            let fetchedItems = try appDelegate.context().fetch(fetchItems) as! [FileSaveModel]

            if fetchedItems.count>0 {
                print(fetchedItems[0].name)
            }

        } catch {
            fatalError("Failed to fetch: \(error)")
        }
    }

Answer 1

如果我理解你的问题。

选择 xcdatamodeld -> 你的实体 -> 数据模块检查器 -> 模块

如果是当前产品模块，将其更改为全局命名空间