I have the following objective-c class:
#interface LatLongData {
NSMutableString *_lat;
NSMutableString *_long;
NSMutableString *_altitude;
}
-(LatLongData*) initWithLat:(NSMutableString*) latitude Long:(NSMutableString*) longitude Altitude:(NSMutableString*) altitude;
#end
How can I store/load an instance of that object? I have tried working with code like this:
LatLongData *data = [[LatLongData alloc] initWithLat:_lat Long:_long Altitude:_altitude];
// Save
NSData *theData = [NSKeyedArchiver archivedDataWithRootObject:data];
[[NSUserDefaults standardUserDefaults] setObject:theData forKey:LatLongDataKey];
//...
// Load
NSData *loadedData = [[NSUserDefaults standardUserDefaults] dataForKey:LatLongDataKey];
LatLongData *ldata = (LatLongData *)[NSKeyedUnarchiver unarchiveObjectWithData:theData];
But I have no luck with that...
I know I should read everything about Core Data. I will but at this point it would be very nice to get my little sample to work.
You need to use NSCoding protocol with your class.
#interface LatLongData <NSCoding>
Here are a few protocol methods:
- (id)initWithCoder:(NSCoder *)aDecoder
{
if ((self = [super init])) {
lat = [[aDecoder decodeObjectForKey:#"lat"] copy];
long = [[aDecoder decodeObjectForKey:#"long"] copy];
alt = [[aDecoder decodeObjectForKey:#"alt"] copy];
}
return self;
}
- (void)encodeWithCoder:(NSCoder *)aCoder
{
[aCoder encodeObject:lat forKey:#"lat"];
[aCoder encodeObject:long forKey:#"long"];
[aCoder encodeObject:alt forKey:#"alt"];
}
P.S. You need to replace theData at your last line with loadedData
Related
This question will seem a copy, but it is not.
My Contact class confirms to NSCoding protocol, implementing methods:
#pragma mark Encoding/Decoding
-(void)encodeWithCoder:(NSCoder *)aCoder
{
NSLog(#"Encoding");
[aCoder encodeObject:self.firstName forKey:#"firstName"];
NSLog(#"First name encoded");
[aCoder encodeObject:self.lastName forKey:#"lastName"];
NSLog(#"Last name encoded");
[aCoder encodeInt:self.age forKey:#"age"];
NSLog(#"Age encoded");
[aCoder encodeObject:self.phoneNumbers forKey:#"phoneNumbers"];
NSLog(#"Encoding finished");
}
- (id) initWithCoder: (NSCoder *)coder
{
if (self = [super init])
{
[self setFirstName:[coder decodeObjectForKey:#"firstName"]];
[self setLastName:[coder decodeObjectForKey:#"lastName"]];
[self setPhoneNumbers:[coder decodeObjectForKey:#"phoneNumbers"]];
[self setAge:[coder decodeIntForKey:#"age"]];
}
return self;
}
PhoneNumbers is a dictionary, when encoding reaches to encode it, the application crashes. And this is how I serialize Contacts array:
#pragma mark Import/Export
//Export Contacts to file
-(void)exportContactsToFile
{
BOOL done=[NSKeyedArchiver archiveRootObject:self.contacts toFile:[PathUtility getFilePath:#"phonebook"]];
}
//Import Contacts from file
-(void)importContactsFromFile
{
self.contacts = [NSKeyedUnarchiver unarchiveObjectWithFile:[PathUtility getFilePath:#"phonebook"]];
}
how should I serialize NSDictionary as property?
Thanks
The NSPropertyListSerialization class provides the serialization methods that convert property list objects to and from either an XML or an optimized binary format. The NSPropertyListSerialization class object provides the interface to the serialization process; you don’t create instances of NSPropertyListSerialization.
NSDictionary *propertyList= #{ #"FirstNameKey" : #"Edmund",
#"LastNameKey" : #"Blackadder" };
NSString *errorStr;
NSData *dataRep = [NSPropertyListSerialization dataFromPropertyList:propertyList
format:NSPropertyListXMLFormat_v1_0
errorDescription:&errorStr];
if (!dataRep) {
// Handle error
}
I am writing a basic game, I am using a GameStateManager which is a singleton and handles all state management, such as saves, loads, delete methods.
I have a separate singelton which handles all the Game stuff. The game object is inside the game state manager so I can save it out using NSCoding and Archiving.
When I save the state there appears to be no issues and the Game object (singleton) is saved properly.
However, when I try to load the state (by relaunching the app), the game object is always null.
Strangley, if I remove the singleton properties and make it a standard class, this issue goes away and I can load the class and all its properties without any major issues.
In summary, I do this:
GameStateManager = Singleton, handles all game state management (load, save) and has a game object (game)
Game = Singleton which handles things within the game and has NSCoding protocol employed.
Saving the game state with the game object is fine, the object is clearly there.
Loading the game state seems to make the game object null. It should be there, but for some reason it never loads it.
If I remove all the properties that make the game class a singelton and make it a normal class, the issue seems to go away.
I think it has something to do with the fact that Game is never init'd, but this does not make sense because I can get Game to load when it has no singleton properties.
Code now follows.
// GameStateManager.m
-(void)saveGameState
{
CCLOG(#"METHOD: saveGameState()");
self.lastSaveDate = [NSDate date];
NSMutableData *data;
NSString *archivePath = [NSTemporaryDirectory() stringByAppendingPathComponent:kGameSaveFile];
NSKeyedArchiver *archiver;
BOOL result;
data = [NSMutableData data];
archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[archiver encodeObject:self.lastSaveDate forKey:#"lastSaveDate"];
[archiver encodeObject:self.game forKey:#"game"];
[archiver finishEncoding];
result = [data writeToFile:archivePath atomically:YES];
[archiver release];
}
-(void)loadGameState
{
CCLOG(#"METHOD: loadGameState()");
NSData *data;
NSKeyedUnarchiver *unarchiver;
NSString *archivePath = [NSTemporaryDirectory() stringByAppendingPathComponent:kGameSaveFile];
data = [NSData dataWithContentsOfFile:archivePath];
unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
// Customize unarchiver here
self.game = [unarchiver decodeObjectForKey:#"game"];
self.lastSaveDate = [unarchiver decodeObjectForKey:#"lastSaveDate"];
[unarchiver finishDecoding];
[unarchiver release];
CCLOG(#"Last Save Date = %#", self.lastSaveDate);
NSLog(#"game = %#", self.game);
}
// END OF GAMESTATEMANAGER
// -------------------------
// Game.h
#interface Game : NSObject
<NSCoding>
{
NSMutableArray *listOfCities;
NSMutableArray *listOfColors;
NSMutableArray *listOfPlayers;
}
#property (nonatomic, retain) NSMutableArray *listOfCities;
#property (nonatomic, retain) NSMutableArray *listOfColors;
#property (nonatomic, retain) NSMutableArray *listOfPlayers;
+(Game *) sharedGame;
//
// Game.m
// This is a cut-down version of the game object
// Game is a singelton
// The listOfCities, etc are arrays
//
#implementation Game
SYNTHESIZE_SINGLETON_FOR_CLASS(Game)
#synthesize listOfCities, listOfPlayers;
#pragma mark - NSCoding
-(id)initWithCoder:(NSCoder *)aDecoder
{
self = [super init];
if (self)
{
self.listOfCities = [aDecoder decodeObjectForKey:#"listOfCities"];
self.listOfPlayers = [aDecoder decodeObjectForKey:#"listOfPlayers"];
NSLog(#"Cities = %d", [self.listOfCities count]);
NSLog(#"Players = %d", [self.listOfPlayers count]);
}
return self;
}
-(void)encodeWithCoder:(NSCoder *)aCoder
{
// Archive objects
NSLog(#"Cities = %d", [self.listOfCities count]);
NSLog(#"Players = %d", [self.listOfPlayers count]);
[aCoder encodeObject:self.listOfCities forKey:#"listOfCities"];
[aCoder encodeObject:self.listOfPlayers forKey:#"listOfPlayers"];
}
#end
My question is, how do I successfully save and load an Objective C singelton using NSCoding, and the Archiver?
Edit;
I have tried:
// In the GameStateManager
#pragma mark - NSCoding
-(id)initWithCoder:(NSCoder *)decoder {
if (self = [super init]) {
self.lastSaveDate = [[decoder decodeObjectForKey:#"lastSaveDate"] retain];
self.game = [[decoder decodeObjectForKey:#"game"] retain];
}
return self;
}
-(void)encodeWithCoder:(NSCoder *)encoder {
[encoder encodeObject:self.lastSaveDate forKey:#"lastSaveDate"];
[encoder encodeObject:self.game forKey:#"game"];
}
and
// In Game.m
self.listOfCities = [[aDecoder decodeObjectForKey:#"listOfCities"] retain];
self.listOfPlayers = [[aDecoder decodeObjectForKey:#"listOfPlayers"] retain];
NSLog(#"Cities = %d", [self.listOfCities count]);
NSLog(#"Players = %d", [self.listOfPlayers count]);
Since you're dealing with a singleton, you only ever want a single instance of the class to exist at any time. So you will want to archive and unarchive that single instance only.
Consider this code (assumes ARC is enabled):
#interface Singleton : NSObject <NSCoding>
+ (id)sharedInstance;
#property (strong, nonatomic) NSString *someString;
#end
#implementation Singleton
+ (id)sharedInstance {
static Singleton instance = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
instance = [[Singleton alloc] init];
});
return instance;
}
#pragma mark - NSCoding implementation for singleton
- (id)initWithCoder:(NSCoder *)aDecoder {
// Unarchive the singleton instance.
Singleton *instance = [Singleton sharedInstance];
[instance setSomeString:[aDecoder decodeObjectForKey:#"someStringKey"]];
return instance;
}
- (void)encodeWithCoder:(NSCoder *)aCoder {
// Archive the singleton instance.
Singleton *instance = [Singleton sharedInstance];
[aCoder encodeObject:[instance someString] forKey:#"someStringKey"]];
}
#end
Using this template, you can archive/unarchive the singleton, like this:
// Archiving calls encodeWithCoder: on the singleton instance.
[[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:[Singleton sharedInstance]] forKey:#"key"];
// Unarchiving calls initWithCoder: on the singleton instance.
[[NSKeyedUnarchiver unarchiveObjectWithData:[[NSUserDefaults standardUserDefaults] objectForKey:#"key"]];
try this in your initWithCoder method :
self.listOfCities = [[aDecoder decodeObjectForKey:#"listOfCities"] retain];
self.listOfPlayers = [[aDecoder decodeObjectForKey:#"listOfPlayers"] retain];
Easiest way:
1. Load singleton:
+ (AppState *)sharedInstance
{
static AppState *state = nil;
if ( !state )
{
// load NSData representation of your singleton here.
NSData *data =[[NSUserDefaults standardUserDefaults] objectForKey:#"appStateData"];
if ( data )
{
state = [NSKeyedUnarchiver unarchiveObjectWithData:data];
}
else
{
state = [[AppState alloc] init];
}
}
return state;
}
2. Save singleton on a disk
- (BOOL)save
{
NSData *appStateData = [NSKeyedArchiver archivedDataWithRootObject:self];
// now save NSData to disc or NSUserDefaults.
[[NSUserDefaults standardUserDefaults] setObject:appStateData forKey:#"appStateData"];
}
3. Implement NSCoding methonds:
- (id)initWithCoder:(NSCoder *)coder;
- (void)encodeWithCoder:(NSCoder *)coder;
Done!
I'm using a hybrid approach encompassing answers by Eric Baker and skywinder.
+ (GameStateManager *)sharedInstance {
static GameStateManager *instance = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
NSData *data = [[NSUserDefaults standardUserDefaults] objectForKey:#"key"];
if (data) {
instance = [NSKeyedUnarchiver unarchiveObjectWithData:data];
} else {
instance = [[GameStateManager alloc] init];
}
});
return instance;
}
I have an object that I convert into NSData using an NSKeyedArchiver and then store it into NSUserDefaults. Everything gets saved correctly except for the elements of an array that the object has. All the objects in the array have conform to the NSCoder protocols (or whatever theyre called- ex. self.property = [decoder decodeObjectForKey:#"key"] and [encoder encodeObjectForKey:#"key"])
When I save the object, the elements of the array remain in the array, but their properties themselves do not get saved. i DO call the sycnrhonize method, so that is not the issue.
NOTE that all other times i save & load it is correct, it just does not save the elements of an array that belongs to an object. Do i have to save that separately?
The "current status" NSNumber is not being saved. Objective and target are being saved
import "Level.h"
#implementation Level
#synthesize objective = _objective;
#synthesize isComplete = _isComplete;
#synthesize goldReward = _goldReward;
#synthesize xpReward = _xpReward;
#synthesize missionID = _missionID;
#synthesize currentStatus = _currentStatus;
#synthesize targetName = _targetName;
#synthesize owner = _owner;
-(void)dealloc{
[super dealloc];
}
-(id)initWithMissionID:(int)number{
if (self = [super init]) {
self.currentStatus = 0;
self.isComplete = NO;
self.missionID = [NSNumber numberWithInt:number];
[self setUpMisson];
}
return self;
}
-(void)setUpMisson{
if ([self.missionID intValue] == 0) {
self.xpReward = [NSNumber numberWithInt:100];
self.goldReward = [NSNumber numberWithInt:100];
self.objective = [NSNumber numberWithInt:3];
self.targetName = #"Swordsman";
CCLOG(#"Gotta kill some swordsmen!");
}
}
-(void)encodeWithCoder:(NSCoder *)encoder{
[encoder encodeObject:self.objective forKey:#"objective"];
[encoder encodeObject:self.isComplete forKey:#"isComplete"];
[encoder encodeObject:self.goldReward forKey:#"goldReward"];
[encoder encodeObject:self.xpReward forKey:#"xpReward"];
[encoder encodeObject:self.missionID forKey:#"missionID"];
[encoder encodeObject:self.currentStatus forKey:#"currentStatus"];
[encoder encodeObject:self.targetName forKey:#"targetName"];
[encoder encodeObject:self.owner forKey:#"owner"];
CCLOG(#"SAVING LEVEL");
}
-(id)initWithCoder:(NSCoder *)decoder{
if (self = [super init]) {
self.objective = [[decoder decodeObjectForKey:#"objective"]retain];
self.isComplete = [[decoder decodeObjectForKey:#"isComplete"]retain];
self.goldReward = [[decoder decodeObjectForKey:#"goldReward"]retain];
self.xpReward = [[decoder decodeObjectForKey:#"xpReward"]retain];
self.missionID = [[decoder decodeObjectForKey:#"missionID"]retain];
self.targetName = [[decoder decodeObjectForKey:#"targetName"]retain];
self.owner = [[decoder decodeObjectForKey:#"owner"]retain];
CCLOG(#"LOADING LEVEL");
}
return self;
}
-(void)updateStatusForKill:(AI *)killedTarget{
CCLOG(#"WE KILLED: %# and OUR GOAL IS: %#",killedTarget.name,self.targetName);
if ([killedTarget.name isEqualToString:self.targetName]) {
[self setCurrentStatus:[NSNumber numberWithInt:[self.currentStatus intValue]+1]];
CCLOG(#"Current Status: %i Objective: %i", [self.currentStatus intValue],[self.objective intValue]);
if ([self.currentStatus intValue] == [self.objective intValue]) {
[self completeMission];
}
}
}
-(void)completeMission{
[self.owner setCoins:[NSNumber numberWithInt:[[self.owner coins]intValue] + [self.goldReward intValue]]];
[self.owner setXp:[NSNumber numberWithInt:[[self.owner xp]intValue] + [self.xpReward intValue]]];
CCLOG(#"complete");
[[self.owner missionList]removeObject:self];
}
#end
EDIT: The "owner" refers back to the object being saved. I think this is where the problem is, so I'm removing that and testing again.
EDIT: and that did nothing!
What you describe should "just work." In the encodeWithCoder method of your custom object, you would just encode the array object, and that should cause the array and it's contents to be encoded.
However, if any of the objects in the array do not support NSCoding, that will fail. My guess is that something in your array (or it's children or grandchildren) does not support NSCoding.
I ran into this problem when trying to save an array of Accounts that contain property values and another custom object. I couldn't save my data with your proposed solution because I was arbitrarily adding accounts to an array, and it wouldn't make sense to come up with unique identifiers for dynamically added accounts. I ended up nesting the NSCoding protocol:
In my AccountManager class:
- (void) saveAllAccounts {
[self deleteAllAccounts]; //Just removes whatever was previously stored there
[[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:accountArray] forKey:saveAccountsArrayKey];
[[NSUserDefaults standardUserDefaults] synchronize];
}
In my Account class:
- (void) encodeWithCoder:(NSCoder *)aCoder {
[aCoder encodeObject:username forKey:#"username"];
[aCoder encodeObject:token forKey:#"token"];
[aCoder encodeObject:specialID forKey:#"special ID"];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:deviceArray];
[[NSUserDefaults standardUserDefaults] setObject:data forKey:#"device array"];
}
- (id) initWithCoder:(NSCoder *)aDecoder {
self = [super init];
if (self != nil) {
username = [[aDecoder decodeObjectForKey:#"username"] retain];
token = [[aDecoder decodeObjectForKey:#"token"] retain];
ecoID = [[aDecoder decodeObjectForKey:#"eco ID"] retain];
NSData *deviceArrayData = [[NSUserDefaults standardUserDefaults] objectForKey:#"device array"];
if (deviceArrayData != nil) {
NSArray *savedArray = [NSKeyedUnarchiver unarchiveObjectWithData: deviceArrayData];
if (savedArray != nil)
deviceArray = [[NSMutableArray alloc] initWithArray:savedArray];
}
}
return self;
}
In my AccountDevice class:
- (void) encodeWithCoder:(NSCoder *)aCoder {
[aCoder encodeObject:pairingPassword forKey:#"pairing password"];
[aCoder encodeObject:devicePin forKey:#"device pin"];
}
- (id) initWithCoder:(NSCoder *)aDecoder {
self = [super init];
if (self != nil) {
password = [[aDecoder decodeObjectForKey:#"password"] retain];
pin = [[aDecoder decodeObjectForKey:#"pin"] retain];
}
return self;
}
It might be a little buggy because I haven't finished testing it, but my preliminary tests were successful, and I think the concept is there.
It looks like you're using -encodeObject:forKey: and -decodeObjectForKey: even on values that aren't objects. For example, in your -initWithMissionID: you've got:
self.isComplete = NO;
which makes me think that complete is a BOOL property, but your -encodeObject:forKey: says:
[encoder encodeObject:self.isComplete forKey:#"isComplete"];
I think you probably want to call -encodeBool:forKey: instead, like this:
[encoder encodeBool:self.isComplete forKey:#"isComplete"];
On the other hand, I'd really expect some sort of warning if the problem were that simple. Do you get any warnings? It's harder to infer the types of your other properties, but look at each of your properties for the same kind of problem.
found a workaround using a Unique-Id system for each mission and saving the progress for each mission separately into NSUserDefaults which are just then loaded again. Not ideal, but it works. Thanks for everyone's help!
The problem lies within the 'initWithCoder' method. When I want to retrieve "Coins_Key" from where I saved it by calling the 'saveData' method in my 'main' class and I pass in the key "self.keyName," the value of keyName is 0.
//Class coins.h
#property (retain) NSString* keyName;
#property (retain) NSString* keyValue;
//Class coins.m
#synthesize keyName;
-(void) saveData:(NSString *)number: (NSString *)keyID
{
self.keyName = keyID;
self.keyValue = number;
}
- (void)encodeWithCoder:(NSCoder *)encoder {
NSLog(#"Encoded keyName: %#", keyName);
[encoder encodeObject:keyValue forKey:keyName];
}
- (id)initWithCoder:(NSCoder *)decoder {
self.keyValue = [decoder decodeObjectForKey:self.keyName];
NSLog(#"Decoded Coins: %#", self.keyValue);
return self;
}
//Class main
[Coins *coin3 = [[Coins alloc] init];
[coin3 saveData:#"6" :#"Coins_Key"];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:coin3];
coin3 = [NSKeyedUnarchiver unarchiveObjectWithData:data];
You're not quite grasping the encoder/decoder workflow.
Using the encodeObjectForKey: and decodeObjectForKey: methods properly, you should be passing as an argument the key that should be used to store the value. This key must remain constant.
You should also not require callers to provide the key your Coin object uses to store data. Take this simple example as a more correct/efficient method (assuming I understand the purpose of your class):
// Class Coins.h
#property (assign) int numberOfCoins;
// Class Coins.m
#define NUM_COINS_KEY #"NUM_COINS_KEY"
#synthesize numberOfCoins;
- (id)initWithCoder:(NSCoder *)decoder {
if (self = [super init]) { // Use [super initWithCoder:decoder] here if your superclass supports it
self.numberOfCoins = [decoder decodeIntForKey:NUM_COINS_KEY];
NSLog(#"Decoded Coins: %d", self.numberOfCoins);
}
return self;
}
- (void)encodeWithCoder:(NSCoder *)encoder {
NSLog(#"Encoded keyName: %#", keyName);
[encoder encodeInt:self.numberOfCoins forKey:NUM_COINS_KEY];
}
// Class main
Coins *coin = [[Coins alloc] init];
coin.numberOfCoins = 6;
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:coin];
[coin release]; // If you're just playing around, this is probably overkill, but a good habit
coin = [NSKeyedUnarchiver unarchiveObjectWithData:data];
I am trying to save an object in NSUserDefaults but i have not been successful in it. Scenario is that, I have an object syncObject of class SyncObjct. I have implemented following methods in SyncObject class
- (NSMutableDictionary*)toDictionary;
+ (SyncObject*)getFromDictionary :(NSMutableDictionary*)dictionary;
- (id) initWithCoder: (NSCoder *)coder;
- (void) encodeWithCoder: (NSCoder *)coder;
And also the SyncObject class is NSCoding class. Now SyncObject class contains an NSMutableArray with name jobsArray. This array contains objects of class JobsObject. I implemented same above methods for this class as well to make it coding compliant. In toDictionary method of SyncObject class, i am storing this array in dictionary by writing following line.
[dictionary setValue:jobsArray forKey:#"jobsArray"];
and I am retrieving it in getFromDictionary method of SyncOject class by writing following line.
+ (SyncObject*)getFromDictionary :(NSMutableDictionary*)dictionary
{
NSLog(#"SyncObject:getFromDictionary");
SyncObject *syncObject = [[SyncObject alloc] init];
#try
{
syncObject.noOfJobs = [[dictionary valueForKey:#"noOfJobs"] intValue];
syncObject.totalJobsPerformed = (TotalJobsPerformed*)[dictionary valueForKey:#"totalobsPerformed"];
syncObject.jobsArray = [dictionary valueForKey:#"jobsArray"];
}
#catch (NSException * e)
{
NSLog(#"EXCEPTION %#: %#", [e name], [e reason]);
}
#finally
{
}
return syncObject;
}
And also I am storing syncObject in NSUserDefault by writing following lines.
NSData *myEncodedObject = [NSKeyedArchiver archivedDataWithRootObject:syncObject];
[userStorage setObject:myEncodedObject forKey:SYNC_OBJECT];
I am retrieving the object from NSUserDefaults by writing following lines
NSData *myEncodedObject = [userStorage objectForKey: SYNC_OBJECT];
syncObject = (SyncObject*)[NSKeyedUnarchiver unarchiveObjectWithData: myEncodedObject];
Problem is that i am not able to retrieve jobsArray correctly. Some invalid object is returned and app crashes when trying to access it. Please can anyone tell me the reason of this problem?
Best Regards
I believe the problem is that NSUserDefaults does not support storing of custom object types.
From Apple's documentation when using -setObject: The value parameter can be only property list objects: NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary. For NSArray and NSDictionary objects, their contents must be property list objects.
You can review the remaining documentation directly from Apple's NSUserDefault Class Reference manual.
Custom class .h
#import <Foundation/Foundation.h>
#interface Person : NSObject
#property(nonatomic, retain) NSArray *names;
#property(strong,nonatomic)NSString *name;
#end
custom class .m
#import "Person.h"
#implementation Person
#synthesize names;
- (void)encodeWithCoder:(NSCoder *)encoder {
[encoder encodeObject:self.name forKey:#"name"];
}
- (id)initWithCoder:(NSCoder *)decoder {
if((self = [super init])) {
//decode properties, other class vars
self.name = [decoder decodeObjectForKey:#"name"];
}
return self;
}
#end
To create Person class object and store and retrieve your stored data from NSUserDefaults
Stored your object :
#import "ViewController.h"
#import "Person.h"
#interface ViewController ()
#property (weak, nonatomic) IBOutlet UITextField *textBox;
#end
NSMutableArray *arr;
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)saveButton:(id)sender {
Person *person =[Person new];
person.name = _textBox.text;
arr = [[NSMutableArray alloc]init];
[arr addObject:person];
NSData *encodedObject = [NSKeyedArchiver archivedDataWithRootObject:arr];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:encodedObject forKey:#"name"];
[defaults synchronize];
}
- (IBAction)showButton:(id)sender {
_label.text = #"";
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSData *storedEncodedObject = [defaults objectForKey:#"name"];
NSArray *arrStoreObject = [NSKeyedUnarchiver unarchiveObjectWithData:storedEncodedObject];
for (int i=0; i<arrStoreObject.count; i++)
{
Person *storedObject = [arrStoreObject objectAtIndex:i];
_label.text = [NSString stringWithFormat:#"%# %#", _label.text , storedObject.name];
}
}
#end