iOS NSCoding / NSKeyed​Archiver

一：要想使对象可以直接存储，首先要遵循NSCoding协议

@interface Person : NSObject

@property NSString *title;

@property NSString *author;

@property NSUInteger pageCount;

@property NSSet*categories;

@property (getter= isAvailable) BOOL available;

@end

@implementationPerson

- (id)initWithCoder:(NSCoder*)decoder {

    self= [super init];

    if(!self) {

        return nil;

    }

    self.title= [decoder decodeObjectForKey:@"title"];

    self.author= [decoder decodeObjectForKey:@"author"];

    self.pageCount= [decoder decodeIntegerForKey:@"pageCount"];

    self.categories= [decoder decodeObjectForKey:@"categories"];

    self.available= [decoder decodeBoolForKey:@"available"];

    return self;

}

- (void)encodeWithCoder:(NSCoder*)encoder {

    [encoder encodeObject:self.title forKey:@"title"];

    [encoder encodeObject:self.author forKey:@"author"];

    [encoder encodeInteger:self.pageCount forKey:@"pageCount"];

    [encoder encodeObject:self.categories forKey:@"categories"];

    [encoder encodeBool:[self isAvailable] forKey:@"available"];

}

创建需要archiver的对象

    Person *p = [[Person alloc] init];

    p.title = @"蒙奇 D 路飞";

    p.author=@"test1";

    p.pageCount=1;

    p.categories = [NSSet setWithObjects:@"a", @"b", nil];

    p.available=YES;

     NSString *home = NSHomeDirectory();

    home = [home stringByAppendingPathComponent:@"test.txt"];

    //存储数据

    BOOL res = [NSKeyedArchiver archiveRootObject:p toFile:home];

    //获取数据

    Persion *p1 = [NSKeyedUnarchiver unarchiveObjectWithFile:home];

    //存储数据

     NSData *data = [NSKeyedArchiver archivedDataWithRootObject:p];

    [[NSUserDefaults standardUserDefaults] setObject:data forKey:@"person"];

    //获取数据

    NSData *data = [[NSUserDefaults standardUserDefaults] objectForKey:@"person"];

    Person *person = [NSKeyedUnarchiver unarchiveObjectWithData:data];

二：对象具有copy功能

person.h，person.m如下

@interface Person : NSObject<NSCopying>

@property (nonatomic, assign) NSInteger age;

@property (nonatomic, copy) NSString *name;

@end

@implementation Person

- (id)copyWithZone:(NSZone*)zone {

    Person *person = [[[self class] allocWithZone:zone] init];

    person.age = self.age;

    person.name = self.name;

    return person;

}

@end

控制器里边测试如下：

   Person *person = [[Person alloc]init]; 

    person.age = 10;

    person.name = @"name"; 

    Person*person1 = [person copy];

    person1.age=11;

    person1.name=@"name1";

    NSLog(@"person.age==%ld", person.age);//person.age==10

    NSLog(@"person.name==%@", person.name);//person.name==name

    NSLog(@"person1.age==%ld", person1.age);//person1.age==11

    NSLog(@"person1.name==%@", person1.name);//person1.name==name1