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!


当前回答

Swift- 4 Xcode 9.1

试试这段代码

你不能存储映射器在NSUserDefault,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)

其他回答

保存:

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

得到:

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

为消除

[currentDefaults removeObjectForKey:@"yourKeyName"];

首先,rmaddy的答案(上面)是正确的:实现NSCoding没有帮助。然而,你需要实现NSCoding来使用NSKeyedArchiver和所有这些,所以这只是一个多步骤…通过NSData转换。

例子的方法

- (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];
}

所以你可以把你的NSCoding对象包装在NSArray或NSDictionary中。

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

我有这个问题,试图保存一个字典到NSUserDefaults。结果是它不能保存,因为它包含NSNull值。所以我只是复制字典到一个可变字典删除空值,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。

Swift- 4 Xcode 9.1

试试这段代码

你不能存储映射器在NSUserDefault,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)