iOS：文件归档和解归档的详解和使用

1 NSArray *documents = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 2 3 NSString *documentPath = [documents lastObject]; 4 5 NSString *archiveFileName = [documentPath stringByAppendingPathComponent:@"array.arc"];

1 NSArray *array = @[@1,@5,@3,@3,@4,@2];

1 if([NSKeyedArchiver archiveRootObject:array toFile:archiveFileName]) 2 3  { 4 5 NSLog(@"归档对象成功"); 6 7 } 

1 NSArray *array2 = [NSKeyedUnarchiver unarchiveObjectWithFile:archiveFileName];

1 #import <Foundation/Foundation.h> 2 @interface Person : NSObject<NSCoding> 3 @property (copy,nonatomic)NSString *name; 4 @property (assign,nonatomic)NSInteger age; 5 @property (assign,nonatomic)char gender; 6 -(id)initWithName:(NSString*)name andAge:(NSInteger)age andChar:(char)gender; 7 @end

 1 #import "Person.h"  2 @implementation Person  3 -(id)initWithName:(NSString*)name andAge:(NSInteger)age andChar:(char)gender  4 {  5 self = [super init];  6 if(self)  7  {  8 _name = [name copy];  9 _age = age; 10 _gender = gender; 11  } 12 return self; 13 } 14 -(NSString*)description 15 { 16 return [NSString stringWithFormat:@"name:%@,age:%ld,gender:%c",_name,_age,_gender]; 17 } 18 #pragma mark -<NSCoding> 19 //归档的协议方法 20 -(void)encodeWithCoder:(NSCoder *)aCoder//将归档对象序列化 21 { 22 [aCoder encodeObject:_name forKey:@"name"]; 23 [aCoder encodeInteger:_age forKey:@"age"]; 24 [aCoder encodeInt:_gender forKey:@"gender"]; 25 } 26 //解归档的协议方法 27 -(id)initWithCoder:(NSCoder *)aDecoder //将归档对象反序列化 28 { 29 self = [super init]; 30 if(self) 31  { 32 _name = [[aDecoder decodeObjectForKey:@"name"] copy]; 33 _age = [aDecoder decodeIntegerForKey:@"age"]; 34 _gender = [aDecoder decodeIntForKey:@"gender"]; 35  } 36 return self; 37 } 38 @end

1 NSString *homePath = NSHomeDirectory(); 2 3 NSString *documentPath = [homePath stringByAppendingPathComponent:@"documents"]; 4 5 NSString *arcviFileName = [documentPath stringByAppendingPathComponent:@"person.arc"];

1 Person *person = [[Person alloc]initWithName:@"Tom" andAge:23 andChar:'M'];

1 if([NSKeyedArchiver archiveRootObject:person toFile:arcviFileName]) 2  { 3 NSLog(@"归档成功"); 4  } 5 else 6  { 7 NSLog(@"归档失败"); 8 }

1 Person *person2 = [NSKeyedUnarchiver unarchiveObjectWithFile:arcviFileName];

1 NSArray *documents = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 2 NSString *documentPath = [documents lastObject]; 3 NSString *archiveFileName = [documentPath stringByAppendingPathComponent:@"objects.arc"];

1 NSString *useName = @"admin"; 2 NSArray *scores = @[@90,@89,@90.5,@98]; 3 NSString *adress = @"北京市昌平区东三旗";

 1 //归档多个对象(将多个对象读到data中)  2 //1.用一个可变的data对象创建归档对象  3 NSMutableData *data = [[NSMutableData alloc]init];  4 NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc]initForWritingWithMutableData:data];  5  6 //2.归档多个对象  7 [archiver encodeObject:useName forKey:@"userName"];  8 [archiver encodeObject:scores forKey:@"scores"];  9 [archiver encodeObject:adress forKey:@"adress"]; 10 11 //3.完成归档（必须要实现的方法,要不然归档失败） 12  [archiver finishEncoding]; 13 14 //4.将可变的data写进文件 15 [data writeToFile:archiveFileName atomically:YES];

说明：这种归档方式，其实就是先将所有的要归档的对象先存入到一个可变的NSMutableData对象data中，然后通过data创建的归档对象将data的数据归档到归档文件中就是了。

 1 //解归档多个对象  2 //1.从文件中读出一个data  3 NSData *data2 = [NSData dataWithContentsOfFile:archiveFileName];  4 //2.由data创建解归档对象  5 NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc]initForReadingWithData:data2];  6  7 //3.按照key解出多个对象  8 NSString *userName2 = [unarchiver decodeObjectForKey:@"userName"];  9 NSArray *scores2 = [unarchiver decodeObjectForKey:@"scores"]; 10 NSString *adress2 = [unarchiver decodeObjectForKey:@"adress"]; 11 12 NSLog(@"uesrName:%@,scores:%@,adress:%@",userName2,scores2,adress2);

说明：这种解归档方式，其实就是从归档文件先读取data，然后通过data创建解归档对象根据指定的键将多个对象都解归档出来就是了。

2015-09-20 11:16:56.563 05-一个文件多个归档[908:42275] uesrName:admin,scores:( 90, 89, "90.5", 98 ),adress:北京市昌平区东三旗