数据持久化------Archiving(归档,解档)

其中TRPerson为自定义的继承自NSObject的类的子类  其中有两个属性,name 和 age

.h文件

#import

@interface TRPerson : NSObject<</span>NSCoding>

@property (nonatomic,strong)NSString *name;

@property (nonatomic,strong)NSNumber * age;

//初始化方法

- (id)initWithName:(NSString*)name withAge:(NSNumber *)age;

@end

.m文件

#import "TRPerson.h"

@implementation TRPerson

- (id)initWithName:(NSString *)name withAge:(NSNumber *)age{

if (self=[super init]) {

self.age=age;

self.name=name;

}

return  self;

}

#pragma mark - NSCoding

//对属性进行解码(时机:执行encodeObject方法)

- (instancetype)initWithCoder:(NSCoder *)aDecoder{

self= [super init];

if (self) {

self.name= [aDecoder decodeObjectForKey:@"name"];

self.age=[aDecoder decodeObjectForKey:@"age"];

}

return self;

}

//对属性进行编码的方法

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

[aCoder encodeObject:self.age forKey:@"age"];

[aCoder encodeObject:self.name forKey:@"name"];

}

- (NSString *)description{

TRPerson *person=[[TRPerson alloc]initWithName:self.name withAge:self.age];

return  [NSString stringWithFormat:@"name:%@ age:%@",person.name ,person.age];

}

@end

ViewController中的viewDidLoad方法中实现数据的归档和解挡

- (void)viewDidLoad {

[super viewDidLoad];

//准备工作

//将自定义的TRPerson对象进行归档(写)

TRPerson *person=[[TRPerson alloc]initWithName:@"张飞" withAge:@20];

//Documents/archiving

NSString *doumentsPath =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES).firstObject;

NSString *archiverPath = [doumentsPath stringByAppendingPathComponent:@"archving"];

//1.可变数据类型

NSMutableData *data=[NSMutableData data];

//2.归档对象

NSKeyedArchiver *archiver=[[NSKeyedArchiver alloc]initForWritingWithMutableData:data];

//3.编码

[archiver encodeObject:person forKey:@"person"];

//4.编码完成

[archiver finishEncoding];

//5.写入文件

[data writeToFile:archiverPath atomically:YES];

//将自定义的TRPerson对象进行解挡(读)

//1.读取数据

NSData *readingData=[NSData dataWithContentsOfFile:archiverPath];

//2.解码对象

NSKeyedUnarchiver *unArchiver=[[NSKeyedUnarchiver alloc]initForReadingWithData:readingData];

//3.解码

TRPerson *personRead=[unArchiver decodeObjectForKey:@"person"];

//4.完成解码

[unArchiver finishDecoding];

//验证

NSLog(@"%@",personRead );

}