我有一个CoreData实体SavedWorkout
。它具有以下属性:
completionCounter
是一个Bool
数组,而workout
是一个名为Workout
的自定义类。
我是这样保存我的数据的:
let saveCompletionCounter = currentCompletionCounter
let saveDate = Date() as NSDate
let saveRoutineIndex = Int16(currentWorkoutRoutine)
let saveWorkout = NSKeyedArchiver.archivedData(withRootObject: workout)
item.setValue(saveDate, forKey: "date")
item.setValue(saveWorkout, forKey: "workout")
item.setValue(saveRoutineIndex, forKey: "routineIndex")
item.setValue(saveCompletionCounter, forKey: "completionCounter")
do {
try moc.save()
print("save successful")
} catch {
print("saving error")
}
其中moc
是NSManagedObjectContext
的实例,而item
是NSManagedObject
的实例:
moc = appDelegate.managedObjectContext
entity = NSEntityDescription.entity(forEntityName: "SavedWorkout", in: moc)!
item = NSManagedObject(entity: entity, insertInto: moc)
根据这个和这个以及这个,我已经让我的Workout
类符合NSObject
和NSCoding
,现在它看起来像这样:
class Workout: NSObject, NSCoding {
let name: String
let imageName: String
let routine: [WorkoutRoutine]
let shortDescription: String
required init?(coder aDecoder: NSCoder) {
name = aDecoder.decodeObject(forKey: "name") as! String
imageName = aDecoder.decodeObject(forKey: "imageName") as! String
routine = aDecoder.decodeObject(forKey: "routine") as! [WorkoutRoutine]
shortDescription = aDecoder.decodeObject(forKey: "shortDescription") as! String
}
func encode(with aCoder: NSCoder) {
aCoder.encode(name, forKey: "name")
aCoder.encode(imageName, forKey: "imageName")
aCoder.encode(routine, forKey: "routine")
aCoder.encode(shortDescription, forKey: "shortDescription")
}
init(name: String, imageName: String, routine: [WorkoutRoutine], shortDescription: String) {
self.name = name
self.imageName = imageName
self.routine = routine
self.shortDescription = shortDescription
}
}
然而,我总是在这一行代码上遇到错误:
routine: aDecoder.decodeObject...
。错误提示如下:
NSForwarding: warning: object 0x60800002cbe0 of class 'App.WorkoutRoutine' does not implement methodSignatureForSelector: -- trouble ahead
Unrecognized selector -[FitLift.WorkoutRoutine replacementObjectForKeyedArchiver:]
为什么这会出现错误,而其他的Transformable
属性不会?如何将自定义类保存为CoreData实体的属性?
WorkOutRoutine
的类。那个类也符合NSCoder吗? - AgRizzo