尝试将非属性列表对象设置为NSUserDefaults

Question

我以为我知道是什么导致了这个错误,但我似乎无法弄清楚我做错了什么.

这是我得到的完整错误消息:

Attempt to set a non-property-list object (
   "<BC_Person: 0x8f3c140>"
) as an NSUserDefaults value for key personDataArray

我有一个Person我认为符合NSCoding协议的类,我在这个类中有这两个方法:

- (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;
}

在应用程序的某个时刻,NSString在BC_PersonClass设置中,我有一个DataSave类,我认为正在处理我的属性编码BC_PersonClass.这是我在DataSave课堂上使用的代码:

- (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];
}

我希望这是足够的代码,让你知道我想做什么.我再次知道我的问题在于我如何在我的BC_Person类中编码我的属性,我似乎无法弄清楚虽然我做错了.

谢谢您的帮助!

Answer 1

您发布的代码尝试将一组自定义对象保存到NSUserDefaults.你不能这样做.实现这些NSCoding方法没有帮助.只能存储之类的东西NSArray,NSDictionary,NSString,NSData,NSNumber,和NSDate在NSUserDefaults.

您需要将对象转换为NSData(就像您在某些代码中所拥有的那样)并将其存储NSData在其中NSUserDefaults.你甚至可以存储NSArray的NSData,如果你需要.

当您回读数组时,您需要取消归档NSData以取回BC_Person对象.

也许你想要这个:

- (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"];
}

Answer 2

我自己运行数组并将对象编码为NSData似乎相当浪费.您的错误BC_Person is a non-property-list object告诉您框架不知道如何序列化您的person对象.

因此,所需要的只是确保您的person对象符合NSCoding,然后您只需将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上被破坏,因此操场将存档到数据并返回并打印输出.UserDefaults步骤包括在以后固定的情况下

//: 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")
}

而且,您已将一系列自定义对象存储到NSUserDefaults中

Answer 3

要保存:

NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:yourObject];
[currentDefaults setObject:data forKey:@"yourKeyName"];

要得到:

NSData *data = [currentDefaults objectForKey:@"yourKeyName"];
yourObjectType * token = [NSKeyedUnarchiver unarchiveObjectWithData:data];

删除

[currentDefaults removeObjectForKey:@"yourKeyName"];

Answer 4

Swift 3解决方案

简单的实用类

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")

    }
}

怎么打电话

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!)")
}

Answer 5

Swift-4 Xcode 9.1

试试这段代码

你不能在NSUserDefault中存储mapper,你只能存储NSData,NSString,NSNumber,NSDate,NSArray或NSDictionary.

let myData = NSKeyedArchiver.archivedData(withRootObject: myJson)
UserDefaults.standard.set(myData, forKey: "userJson")

let recovedUserJsonData = UserDefaults.standard.object(forKey: "userJson")
let recovedUserJson = NSKeyedUnarchiver.unarchiveObject(with: recovedUserJsonData)

Answer 6

斯威夫特与@propertyWrapper

将Codable对象保存到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
}

示例用户模型确认可编码

struct User:Codable {
    let name:String
    let pass:String
}

如何使用它

//Set value 
 GlobalSettings.user = User(name: "Ahmed", pass: "Ahmed")

//GetValue
print(GlobalSettings.user)

Answer 7

首先,rmaddy的答案(上图)是对的:实施NSCoding没有帮助.但是,你需要实现NSCoding使用NSKeyedArchiver和所有这些,所以它只是一步...转换通过NSData.

示例方法

- (NSUserDefaults *) defaults {
    return [NSUserDefaults standardUserDefaults];
}

- (void) persistObj:(id)value forKey:(NSString *)key {
    [self.defaults setObject:value  forKey:key];
    [self.defaults synchronize];
}

- (void) persistObjAsData:(id)encodableObject forKey:(NSString *)key {
    NSData *data = [NSKeyedArchiver archivedDataWithRootObject:encodableObject];
    [self persistObj:data forKey:key];
}    

- (id) objectFromDataWithKey:(NSString*)key {
    NSData *data = [self.defaults objectForKey:key];
    return [NSKeyedUnarchiver unarchiveObjectWithData:data];
}

所以,你可以用你的NSCoding对象在一个NSArray或NSDictionary或任何...

Answer 8

我尝试保存字典时遇到了这个问题NSUserDefaults.事实证明它不会保存,因为它包含NSNull值.所以我只是将字典复制到一个可变字典中,删除了空值然后保存到NSUserDefaults

NSMutableDictionary* dictionary = [NSMutableDictionary dictionaryWithDictionary:dictionary_trying_to_save];
[dictionary removeObjectForKey:@"NullKey"];
[[NSUserDefaults standardUserDefaults] setObject:dictionary forKey:@"key"];

在这种情况下,我知道哪些键可能是NSNull值.

Answer 9

\n

https://developer.apple.com/reference/foundation/userdefaults

\n

默认对象必须是属性列表\xe2\x80\x94，即 NSData、NSString、NSNumber、NSDate、NSArray 或 NSDictionary 的实例（或者对于集合，实例的组合）。

\n

如果要存储任何其他类型的对象，通常应该将其存档以创建 NSData 的实例。有关更多详细信息，请参阅首选项和设置编程指南。

\n

\n

Answer 10

Swift 5：可以使用Codable协议代替NSKeyedArchiever。

struct User: Codable {
    let id: String
    let mail: String
    let fullName: String
}

在县结构是围绕UserDefaults标准的对象定义包装。

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)
            }
        }
    }
}

所以你可以这样使用它：

Pref.user?.name = "John"

if let user = Pref.user {...