iOS Core Data: 存储自定义对象 Save Custom NSObject

AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSManagedObject *newContact;
newContact = [NSEntityDescription insertNewObjectForEntityForName:@"Contact" inManagedObjectContext:context];

Person *person = [[Person alloc] init];
person.name = @"Xiaoming";
person.number = @"1008610086";

Birthday *birthday = [[Birthday alloc] init];
birthday.year = @"2000";
birthday.month = @"January";
birthday.day = @"1st";
person.birthday = birthday;

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:person];
[newContact setValue:data forKey:@"person"];

NSError *error;
[context save:&error];

AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
NSFetchRequest *request = [[NSFetchRequest alloc] init];

NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Contact" inManagedObjectContext:context];
[request setEntity:entityDesc];

NSManagedObject *matches = nil;

NSError *error;
NSArray *objects = [context executeFetchRequest:request
error:&error];

if ([objects count] == 0)
{
NSLog(@"No matches");
}
else
{
for (int i = 0; i < [objects count]; i++)
{
matches = objects[i];
NSData *data = [matches valueForKey:@"person"];
Person *person = [NSKeyedUnarchiver unarchiveObjectWithData:data];
NSLog(@"My name is %@. I was born on %@ %@, %@. My phone number is %@", person.name, person.birthday.month, person.birthday.day, person.birthday.year, person.number);
}
}

//
//  Person.h
//  CoreDataTest
//

#import <Foundation/Foundation.h>
#import "Birthday.h"

@interface Person : NSObject<NSCoding>

@property (strong, nonatomic) NSString *name;
@property (strong, nonatomic) NSString *number;
@property (strong, nonatomic) Birthday *birthday;

- (id)init;

@end

//
//  Person.m
//  CoreDataTest
//

#import "Person.h"

@implementation Person

- (id)init{
self.name  = nil;
self.number  = nil;

return self;
}

- (id)initWithCoder:(NSCoder *)decoder{
if (self = [super init]){
self.name  = [decoder decodeObjectForKey: @"name"];
self.number  = [decoder decodeObjectForKey: @"number"];
self.birthday = [decoder decodeObjectForKey: @"birthday"];
}

return self;
}

- (void)encodeWithCoder:(NSCoder *)encoder{
[encoder encodeObject:self.name forKey:@"name"];
[encoder encodeObject:self.number forKey:@"number"];
[encoder encodeObject:self.birthday forKey:@"birthday"];
}

@end

//
//  Birthday.h
//  CoreDataTest
//

#import <Foundation/Foundation.h>

@interface Birthday : NSObject<NSCoding>

@property (strong, nonatomic) NSString *year;
@property (strong, nonatomic) NSString *month;
@property (strong, nonatomic) NSString *day;

- (id)init;

@end

//
//  Birthday.m
//  CoreDataTest
//

#import "Birthday.h"

@implementation Birthday

- (id)init{
self.year  = nil;
self.month  = nil;
self.day  = nil;

return self;
}

- (id)initWithCoder:(NSCoder *)decoder{
if (self = [super init]){
self.year  = [decoder decodeObjectForKey: @"year"];
self.month  = [decoder decodeObjectForKey: @"month"];
self.day = [decoder decodeObjectForKey: @"day"];
}

return self;
}

- (void)encodeWithCoder:(NSCoder *)encoder{
[encoder encodeObject:self.year forKey:@"year"];
[encoder encodeObject:self.month forKey:@"month"];
[encoder encodeObject:self.day forKey:@"day"];
}

@end