对象归档的定义：

对象归档就是将对象归档以文件的形式保存到磁盘中，使用的时候以该文件保存的路径读取文件中的内容

使用NSKeyedArichiver进行归档、NSKeyedUnarchiver进行接档，这种方式会在写入、读出数据之前对数据进行序列化、反序列化操作。

单对象归档，多个对象归档，自定义对象归档

常用的归档一般用在工具类中，对不可变的数据进行归档，可变的数据不进行归档，用起来更加方便

//1.一个对象归档

NSString *homeDictionary = NSHomeDirectory();//获取根目录

NSString *homePath = [homeDictionary stringByAppendingPathComponent:@"archiver.data"];//添加储存的文件名

//归档 toFile:路径 archiveRootObject:id对象

[NSKeyedArchiver archiveRootObject:@"对象" toFile:homePath];

//接档

id object = [NSKeyedUnarchiver unarchiveObjectWithFile:homePath];

NSLog(@"%@",object);

//2.将多个对象归档

NSMutableData *data = [NSMutableData data];

//归档

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

int aInt = 100;

NSString *aString = @"I is an Apple";

NSDictionary *aDict = @{@"a":@"b",@"c":@"d"};

[archiver encodeObject:@(aInt) forKey:@"aInt"];

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

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

[archiver finishEncoding];

NSString *dataHomePath = [NSHomeDirectory() stringByAppendingPathComponent:@"data.archiver"];

[data writeToFile:dataHomePath atomically:YES];

//接档

NSMutableData *muData = [[NSMutableData alloc]initWithContentsOfFile:dataHomePath];

NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc]initForReadingWithData:muData];

NSInteger anInt = [[unarchiver decodeObjectForKey:@"aInt"] integerValue];

NSString *anString = [unarchiver decodeObjectForKey:@"aString"];

NSDictionary *anDict = [unarchiver decodeObjectForKey:@"aDict"];

[unarchiver finishDecoding];

NSLog(@"anInt=%@,anString=%@,anDict=%@",@(anInt),anString,anDict);

//3.自定义对象归档实现copy协议

#import <Foundation/Foundation.h>

@interface ArchiveCopy : NSObject

@property (copy,nonatomic) NSString *name;

@property (copy,nonatomic) NSString *anAge;

end


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

[aCoder encodeObject:@"name"];

[aCoder encodeObject:@"anAge"];

}



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

if (self = [super init]) {

_name = [aDecoder decodeObjectForKey:@"name"];

_anAge = [aDecoder decodeIntegerForKey:@"anAge"];

}

return self;

}


#pragma mark - NSCoping

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

ArchiveCopy *copy = [[[self class] allocWithZone:zone] init];

copy.name = [self.name copyWithZone:zone];

copy.anAge = [self.address copyWithZone:zone];

return copy;

}