NSKeyedUnarchiver不会返回数据
NSKeyedUnarchiver不会返回数据
提问于 2016-06-09 22:41:41
我正在制作一个跟踪用户锻炼的应用程序。我有两个自定义类，第一个是ExerciseModel，，它保存锻炼期间执行的每个练习的数据，包括名称、集合、代表等等。下面是我的数据模型：
import UIKit
class ExerciseModel: NSObject, NSCoding
{
// MARK: Properties
var name: String
var sets: Int
var reps: Int
var heartrate: Int?
var type: String?
//MARK: Archiving Paths
static let DocumentsDirectory = NSFileManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first!
static let ArchiveURL = DocumentsDirectory.URLByAppendingPathComponent("exercises")
// MARK: Initialization
init?(name: String, sets: Int, reps: Int, heartrate: Int?, type: String)
{
// MARK: Initlaize stored properties
self.name = name
self.sets = sets
self.reps = reps
self.heartrate = heartrate
self.type = type
super.init()
// Initialization should fail if there is no name or sets is negative
if name.isEmpty || sets < 0
{
return nil
}
}
struct PropertyKey
{
static let nameKey = "name"
static let setKey = "sets"
static let repKey = "reps"
static let heartrateKey = "heartrate"
static let typekey = "type"
}
// MARK: NSCoding
func encodeWithCoder(aCoder: NSCoder)
{
aCoder.encodeObject(name, forKey: PropertyKey.nameKey)
aCoder.encodeInteger(sets, forKey: PropertyKey.setKey)
aCoder.encodeInteger(reps, forKey: PropertyKey.repKey)
aCoder.encodeObject(type, forKey: PropertyKey.typekey)
}
required convenience init?(coder aDecoder: NSCoder)
{
let name = aDecoder.decodeObjectForKey(PropertyKey.nameKey) as! String
let sets = aDecoder.decodeIntegerForKey(PropertyKey.setKey)
let reps = aDecoder.decodeIntegerForKey(PropertyKey.repKey)
let heartrate = aDecoder.decodeIntegerForKey(PropertyKey.heartrateKey)
let type = aDecoder.decodeObjectForKey(PropertyKey.typekey) as? String
// Must call designated initializer
self.init(name: name, sets: sets, reps: reps, heartrate: heartrate, type: type!)
}
init?(name: String, sets: Int, reps: Int, heartrate: Int, type: String)
{
// Initialize stored properties.
self.name = name
self.sets = sets
self.reps = reps
self.heartrate = heartrate
self.type = type
}
}我的第二个自定义类名为WorkoutStorage，，这意味着允许用户保存整个训练并在以后检索它们。习题属性是上面描述的ExerciseModel对象的数组。以下是我的WorkoutStorage数据模型：
//
import UIKit
@objc(WorkoutStorage)
class WorkoutStorage: NSObject, NSCoding
{
// MARK: Properties
var name: String
var date: NSDate
var exercises: [ExerciseModel]
var maxHR: Int
var avgHR: Int
// MARK: Archiving Paths
static let DocumentsDirectory = NSFileManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first!
static let ArchiveURL = DocumentsDirectory.URLByAppendingPathComponent("storedWorkouts")
// MARK: Initialization
init?(name: String, date: NSDate, exercises: [ExerciseModel], maxHR: Int, avgHR: Int)
{
//MARK: Initialize Stored Properties
self.name = name
self.date = date
self.exercises = exercises
self.maxHR = maxHR
self.avgHR = avgHR
super.init()
}
struct PropertyKey
{
static let nameKey = "name"
static let dateKey = "date"
static let exercisesKey = "exercises"
static let maxHRKey = "maxHR"
static let avgHRKey = "avgHR"
}
// MARK: NSCoding
func encodeWithCoder(aCoder: NSCoder)
{
aCoder.encodeObject(name, forKey: PropertyKey.nameKey)
aCoder.encodeObject(date, forKey: PropertyKey.dateKey)
aCoder.encodeObject(exercises, forKey: PropertyKey.exercisesKey)
aCoder.encodeInteger(maxHR, forKey: PropertyKey.maxHRKey)
aCoder.encodeInteger(avgHR, forKey: PropertyKey.avgHRKey)
}
required convenience init?(coder aDecoder: NSCoder)
{
let name = aDecoder.decodeObjectForKey(PropertyKey.nameKey) as! String
let date = aDecoder.decodeObjectForKey(PropertyKey.dateKey) as! NSDate
let exercises = aDecoder.decodeObjectForKey(PropertyKey.exercisesKey) as! [ExerciseModel]
let maxHR = aDecoder.decodeIntegerForKey(PropertyKey.maxHRKey)
let avgHR = aDecoder.decodeIntegerForKey(PropertyKey.avgHRKey)
// Must call designated initializer
self.init(name: name, date: date, exercises: exercises, maxHR: maxHR, avgHR: avgHR)
}
}我学习了Apple教程中的持久化数据来设置NSKeyedArchiver和NSKeyedUnarchiver，但是我仍然很难检索到数据。当我尝试加载训练时，我调用以下函数：
func loadStoredWorkouts() -> WorkoutStorage
{
NSKeyedUnarchiver.setClass(WorkoutStorage.self, forClassName: "WorkoutStorage")
NSKeyedArchiver.setClassName("WorkoutStorage", forClass: WorkoutStorage.self)
print("\(WorkoutStorage.ArchiveURL.path!)")
return NSKeyedUnarchiver.unarchiveObjectWithFile(WorkoutStorage.ArchiveURL.path!) as! WorkoutStorage
}目前我只能返回一个WorkoutStorage对象，但是当我试图检索一个包含所有存储的WorkoutStorage对象的数组时，我会收到一个错误消息：不能将'Workout_Tracker.WorkoutStorage‘(0x1000fcc80)类型的值转换为'NSArray’(0x19f6b2418)。我阅读了很多文档，试图找出为什么这只会返回一个对象，以及检查出类似问题的问题，但都没有用。最初，我按照教程设置了我的应用程序来存储和加载我的ExerciseModel对象，这似乎是完美无缺的。我以同样的方式设置了WorkoutStorage类，但这里似乎存在一个问题。
任何帮助都将不胜感激！！
**Edit*下面是我用来归档WorkoutStorage对象的代码：
func saveWorkoutStorageObject(currentWorkout: WorkoutStorage)
{
NSKeyedUnarchiver.setClass(WorkoutStorage.self, forClassName: "WorkoutStorage")
NSKeyedArchiver.setClassName("WorkoutStorage", forClass: WorkoutStorage.self)
let isSuccessfulSave = NSKeyedArchiver.archiveRootObject(currentWorkout, toFile: WorkoutStorage.ArchiveURL.path!)
if !isSuccessfulSave
{
print("Failed to save exercises")
}
if isSuccessfulSave
{
print("Successful save of current workout: \(currentWorkout)")
}
}用户每次只创建一个锻炼，所以每次完成时，我都会将对象传递给上面的函数来存档。
为了对所有对象进行解压缩，我试图按以下方式进行如下操作：
var workouts = [WorkoutStorage]()
override func viewDidLoad()
{
super.viewDidLoad()
workouts = loadStoredWorkouts()
}其中loadStoredWorkouts()函数为：
func loadStoredWorkouts() -> [WorkoutStorage]
{
NSKeyedUnarchiver.setClass(WorkoutStorage.self, forClassName: "WorkoutStorage")
NSKeyedArchiver.setClassName("WorkoutStorage", forClass: WorkoutStorage.self)
print("\(WorkoutStorage.ArchiveURL.path!)")
return NSKeyedUnarchiver.unarchiveObjectWithFile(WorkoutStorage.ArchiveURL.path!) as! [WorkoutStorage]
}回答 1
Stack Overflow用户
回答已采纳
发布于 2016-06-09 23:31:50
你的saveWorkoutStorageObject只记录了一次锻炼。它不对数组进行存档，因此当然不能将数组解压缩。
如果希望能够解压缩数组，则需要对workouts数组进行归档。
每次将某些文件存档到文件中时，都会替换该文件的内容。它没有附加到结尾。
由于NSKeyedArchiver.archiveRootObject自动归档子对象，所以您所需要做的就是归档数组，并且WorkoutStorage对象将自动归档。
func saveWorkouts(workouts:[WorkoutStorage])
{
let isSuccessfulSave = NSKeyedArchiver.archiveRootObject(workouts, toFile: WorkoutStorage.ArchiveURL.path!)
if isSuccessfulSave
{
print("Successful save of workouts: \(workouts)")
} else {
print("Failed to save exercises")
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/37737351
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