iOS 对象的归档

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;}