ios - 魔法记录 - MR_createEntity 返回 nil

Question

我无法找出我的代码有什么问题。我正在尝试将 MagicalRecord 与 Swift 一起使用。当我做简单的 createEntity 时，它给了我 nil:

let a = Subject.MR_createEntity() <--- This line is working perfectly
let b = Points.MR_createEntity()  <--- This line returns nil
let c = Class.MR_createEntity()   <--- This line returns nil

这是我的类实现:

主题:

@objc(Subject)
class Subject: NSManagedObject {

    @NSManaged var name: String?
    @NSManaged var classes: NSSet?
}

类:

@objc(Class)
class Class: NSManagedObject {

    @NSManaged var name: String?
    @NSManaged var teacherName: String?
    @NSManaged var subject: Subject?
    @NSManaged var points: NSSet?
}

积分:

@objc(Points)
class Points: NSManagedObject {

    @NSManaged var date: NSDate?
    @NSManaged var points: NSNumber?
    @NSManaged var maxPoints: NSNumber?
    @NSManaged var classType: Class?
}

然后来自 .xcdatamodel 的屏幕:

Answer 1

在初始化MagicalRecord时，可以开启core data日志，这样就知道实体创建失败是什么情况了。

MagicalRecord.setLoggingLevel(MagicalRecordLoggingLevel.Warn)