需要编写对象必须实现NSCoding protocol

Person Class

Person.h#import <Foundation/Foundation.h>#import "Face.h"@interface Person : NSObject <NSCoding>@property (nonatomic, strong) NSString      *personId;
@property (nonatomic, strong) NSString      *name;
@property (nonatomic, assign) NSInteger      age;
@property (nonatomic, strong) NSArray       *photos;
@property (nonatomic, strong) NSDictionary  *phoneNumber;@property (nonatomic, strong) Face          *face;@endPerson.m#import "Person.h"@implementation Person
@synthesize personId    = _personId;
@synthesize name        = _name;
@synthesize age         = _age;
@synthesize photos      = _photos;
@synthesize phoneNumber = _phoneNumber;
@synthesize face        = _face;- (id)initWithCoder:(NSCoder *)aDecoder
{if(self = [super init]){self.personId       = [aDecoder decodeObjectForKey:@"id"];self.name           = [aDecoder decodeObjectForKey:@"name"];self.age            = [[aDecoder decodeObjectForKey:@"age"] integerValue];self.photos         = [aDecoder decodeObjectForKey:@"photos"];self.phoneNumber    = [aDecoder decodeObjectForKey:@"phoneNumber"];self.face           = [aDecoder decodeObjectForKey:@"face"];}return self;
}- (void)encodeWithCoder:(NSCoder *)aCoder
{[aCoder encodeObject:self.personId forKey:@"id"];[aCoder encodeObject:self.name forKey:@"name"];[aCoder encodeObject:[NSNumber numberWithInteger:self.age] forKey:@"age"];[aCoder encodeObject:self.photos forKey:@"photos"];[aCoder encodeObject:self.phoneNumber forKey:@"phoneNumber"];[aCoder encodeObject:self.face forKey:@"face"];
}

Face Class

Face.h#import <Foundation/Foundation.h>@interface Face : NSObject <NSCoding>@property (nonatomic, strong) NSString *head;
//@property (nonatomic, strong) NSString *eyes;
//@property (nonatomic, strong) NSString *nose;
//@property (nonatomic, strong) NSString *mouth;
//@property (nonatomic, strong) NSString *ears;@endFace.m#import "Face.h"@implementation Face- (id)initWithCoder:(NSCoder *)aDecoder
{if(self = [super init]){self.head   = [aDecoder decodeObjectForKey:@"head"];}return self;
}- (void)encodeWithCoder:(NSCoder *)aCoder
{[aCoder encodeObject:self.head forKey:@"head"];
}@end

写入和读取操作Person *person = [[Person alloc] init];person.personId = @"123456789";person.name = @"Hunk";person.age = 10;person.photos = @[@"a.png", @"b.png", @"c.png"];person.phoneNumber = @{@"mobile_phone" : @"987654321", @"work" : @"01012345678"};Face *face = [[Face alloc] init];face.head  = @"Round shape";person.face = face;NSData *personData0 = [NSKeyedArchiver archivedDataWithRootObject:person];[[NSUserDefaults standardUserDefaults] setObject:personData0 forKey:@"person"];[[NSUserDefaults standardUserDefaults] synchronize];NSData *personData1 = [[NSUserDefaults standardUserDefaults] objectForKey:@"person"];Person *person1 = [NSKeyedUnarchiver unarchiveObjectWithData:personData1];