我以为我知道是什么导致了这个错误，但我似乎不知道我做错了什么。
以下是我得到的完整错误信息:
Attempt to set a non-property-list object (
"<BC_Person: 0x8f3c140>"
) as an NSUserDefaults value for key personDataArray
我有一个Person类，我认为它符合NSCoding协议，在我的Person类中我有这两个方法:
- (void)encodeWithCoder:(NSCoder *)coder {
[coder encodeObject:self.personsName forKey:@"BCPersonsName"];
[coder encodeObject:self.personsBills forKey:@"BCPersonsBillsArray"];
}
- (id)initWithCoder:(NSCoder *)coder {
self = [super init];
if (self) {
self.personsName = [coder decodeObjectForKey:@"BCPersonsName"];
self.personsBills = [coder decodeObjectForKey:@"BCPersonsBillsArray"];
}
return self;
}
在应用程序的某个地方，NSString在BC_PersonClass中被设置，我有一个DataSave类，我认为它在处理BC_PersonClass中的属性编码。
下面是我从DataSave类中使用的代码:
- (void)savePersonArrayData:(BC_Person *)personObject
{
// NSLog(@"name of the person %@", personObject.personsName);
[mutableDataArray addObject:personObject];
// set the temp array to the mutableData array
tempMuteArray = [NSMutableArray arrayWithArray:mutableDataArray];
// save the person object as nsData
NSData *personEncodedObject = [NSKeyedArchiver archivedDataWithRootObject:personObject];
// first add the person object to the mutable array
[tempMuteArray addObject:personEncodedObject];
// NSLog(@"Objects in the array %lu", (unsigned long)mutableDataArray.count);
// now we set that data array to the mutable array for saving
dataArray = [[NSArray alloc] initWithArray:mutableDataArray];
//dataArray = [NSArray arrayWithArray:mutableDataArray];
// save the object to NS User Defaults
NSUserDefaults *userData = [NSUserDefaults standardUserDefaults];
[userData setObject:dataArray forKey:@"personDataArray"];
[userData synchronize];
}
我希望这些代码足够让您了解我正在尝试做什么。
再次，我知道我的问题在于我是如何编码我的属性在我的BC_Person类，我似乎不能弄清楚什么，虽然我做错了。
谢谢你的帮助!
您发布的代码尝试将一个自定义对象数组保存到NSUserDefaults中。你不能这么做。实现NSCoding方法没有帮助。你只能在NSUserDefaults中存储像NSArray, NSDictionary, NSString, NSData, NSNumber和NSDate这样的东西。
你需要将对象转换为NSData(就像你在一些代码中那样)，并将NSData存储在NSUserDefaults中。如果需要，你甚至可以存储NSData的NSArray。
当你读回数组时，你需要解压缩NSData来得到你的BC_Person对象。
也许你想要这样:
- (void)savePersonArrayData:(BC_Person *)personObject {
[mutableDataArray addObject:personObject];
NSMutableArray *archiveArray = [NSMutableArray arrayWithCapacity:mutableDataArray.count];
for (BC_Person *personObject in mutableDataArray) {
NSData *personEncodedObject = [NSKeyedArchiver archivedDataWithRootObject:personObject];
[archiveArray addObject:personEncodedObject];
}
NSUserDefaults *userData = [NSUserDefaults standardUserDefaults];
[userData setObject:archiveArray forKey:@"personDataArray"];
}
对我来说，自己运行数组并将对象编码到NSData中似乎相当浪费。您的错误BC_Person是一个非属性列表对象，这是在告诉您框架不知道如何序列化您的person对象。
所有需要的是确保你的person对象符合NSCoding然后你可以简单地将你的自定义对象数组转换为NSData并将其存储为默认值。这是一个操场:
编辑:写入NSUserDefaults在Xcode 7上是坏的，所以playground会存档到数据并返回并打印输出。包括UserDefaults步骤，以防它在稍后被修复
//: Playground - noun: a place where people can play
import Foundation
class Person: NSObject, NSCoding {
let surname: String
let firstname: String
required init(firstname:String, surname:String) {
self.firstname = firstname
self.surname = surname
super.init()
}
//MARK: - NSCoding -
required init(coder aDecoder: NSCoder) {
surname = aDecoder.decodeObjectForKey("surname") as! String
firstname = aDecoder.decodeObjectForKey("firstname") as! String
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(firstname, forKey: "firstname")
aCoder.encodeObject(surname, forKey: "surname")
}
}
//: ### Now lets define a function to convert our array to NSData
func archivePeople(people:[Person]) -> NSData {
let archivedObject = NSKeyedArchiver.archivedDataWithRootObject(people as NSArray)
return archivedObject
}
//: ### Create some people
let people = [Person(firstname: "johnny", surname:"appleseed"),Person(firstname: "peter", surname: "mill")]
//: ### Archive our people to NSData
let peopleData = archivePeople(people)
if let unarchivedPeople = NSKeyedUnarchiver.unarchiveObjectWithData(peopleData) as? [Person] {
for person in unarchivedPeople {
print("\(person.firstname), you have been unarchived")
}
} else {
print("Failed to unarchive people")
}
//: ### Lets try use NSUserDefaults
let UserDefaultsPeopleKey = "peoplekey"
func savePeople(people:[Person]) {
let archivedObject = archivePeople(people)
let defaults = NSUserDefaults.standardUserDefaults()
defaults.setObject(archivedObject, forKey: UserDefaultsPeopleKey)
defaults.synchronize()
}
func retrievePeople() -> [Person]? {
if let unarchivedObject = NSUserDefaults.standardUserDefaults().objectForKey(UserDefaultsPeopleKey) as? NSData {
return NSKeyedUnarchiver.unarchiveObjectWithData(unarchivedObject) as? [Person]
}
return nil
}
if let retrievedPeople = retrievePeople() {
for person in retrievedPeople {
print("\(person.firstname), you have been unarchived")
}
} else {
print("Writing to UserDefaults is still broken in playgrounds")
}
瞧，你已经在NSUserDefaults中存储了一个自定义对象数组
Swift 3解决方案
简单实用程序类
class ArchiveUtil {
private static let PeopleKey = "PeopleKey"
private static func archivePeople(people : [Human]) -> NSData {
return NSKeyedArchiver.archivedData(withRootObject: people as NSArray) as NSData
}
static func loadPeople() -> [Human]? {
if let unarchivedObject = UserDefaults.standard.object(forKey: PeopleKey) as? Data {
return NSKeyedUnarchiver.unarchiveObject(with: unarchivedObject as Data) as? [Human]
}
return nil
}
static func savePeople(people : [Human]?) {
let archivedObject = archivePeople(people: people!)
UserDefaults.standard.set(archivedObject, forKey: PeopleKey)
UserDefaults.standard.synchronize()
}
}
模型类
class Human: NSObject, NSCoding {
var name:String?
var age:Int?
required init(n:String, a:Int) {
name = n
age = a
}
required init(coder aDecoder: NSCoder) {
name = aDecoder.decodeObject(forKey: "name") as? String
age = aDecoder.decodeInteger(forKey: "age")
}
public func encode(with aCoder: NSCoder) {
aCoder.encode(name, forKey: "name")
aCoder.encode(age, forKey: "age")
}
}
如何打电话
var people = [Human]()
people.append(Human(n: "Sazzad", a: 21))
people.append(Human(n: "Hissain", a: 22))
people.append(Human(n: "Khan", a: 23))
ArchiveUtil.savePeople(people: people)
let others = ArchiveUtil.loadPeople()
for human in others! {
print("name = \(human.name!), age = \(human.age!)")
}
Swift 5: Codable协议可以用来代替NSKeyedArchiever。
struct User: Codable {
let id: String
let mail: String
let fullName: String
}
Pref结构体是UserDefaults标准对象的自定义包装。
struct Pref {
static let keyUser = "Pref.User"
static var user: User? {
get {
if let data = UserDefaults.standard.object(forKey: keyUser) as? Data {
do {
return try JSONDecoder().decode(User.self, from: data)
} catch {
print("Error while decoding user data")
}
}
return nil
}
set {
if let newValue = newValue {
do {
let data = try JSONEncoder().encode(newValue)
UserDefaults.standard.set(data, forKey: keyUser)
} catch {
print("Error while encoding user data")
}
} else {
UserDefaults.standard.removeObject(forKey: keyUser)
}
}
}
}
所以你可以这样用:
Pref.user?.name = "John"
if let user = Pref.user {...
Swift使用@propertyWrapper
将可编码对象保存为UserDefault
@propertyWrapper
struct UserDefault<T: Codable> {
let key: String
let defaultValue: T
init(_ key: String, defaultValue: T) {
self.key = key
self.defaultValue = defaultValue
}
var wrappedValue: T {
get {
if let data = UserDefaults.standard.object(forKey: key) as? Data,
let user = try? JSONDecoder().decode(T.self, from: data) {
return user
}
return defaultValue
}
set {
if let encoded = try? JSONEncoder().encode(newValue) {
UserDefaults.standard.set(encoded, forKey: key)
}
}
}
}
enum GlobalSettings {
@UserDefault("user", defaultValue: User(name:"",pass:"")) static var user: User
}
用户模型确认可编码
struct User:Codable {
let name:String
let pass:String
}
如何使用
//Set value
GlobalSettings.user = User(name: "Ahmed", pass: "Ahmed")
//GetValue
print(GlobalSettings.user)
我遇到了这个问题，最终发现这是因为我试图使用NSNumber作为字典键，属性列表只允许字符串作为键。setObject:forKey:的文档没有提到这个限制，但是它链接到的About属性列表页面提到了:
By convention, each Cocoa and Core Foundation object listed in Table 2-1 is called a property-list object. Conceptually, you can think of “property list” as being an abstract superclass of all these classes. If you receive a property list object from some method or function, you know that it must be an instance of one of these types, but a priori you may not know which type. If a property-list object is a container (that is, an array or dictionary), all objects contained within it must also be property-list objects. If an array or dictionary contains objects that are not property-list objects, then you cannot save and restore the hierarchy of data using the various property-list methods and functions. And although NSDictionary and CFDictionary objects allow their keys to be objects of any type, if the keys are not string objects, the collections are not property-list objects.
(强调我的)
