归档

归档也叫序列化，是将文件存在硬盘，解档是从硬盘还原

5种方式： 第一种、使用属性列表进行归档 如果对象是NSString，NSDictionary,NSArray,NSData或者NSNumber，可以使用writeToFile:atomically方法将数据写到文件,注意这种方式是明文

sample:

NSArray *array = @[@"abc",@"123",@23.4]; if ([array writeToFile:@"text.plist" atomically:YES]) { NSLog(@"success"); } NSArray *arr2=[NSArray arrayWithContentsOfFile:@"text.plist"]; NSLog(@"%@",arr2);

第二、NSKeyedArchiver–对象归档，数据会加密 1、对于NSArray或者NSDictionary sample code：

/***归档对象****/ NSArray *array = @[@"abc",@"123",@23.4]; NSString *homePath = NSHomeDirectory(); NSString *path = [homePath stringByAppendingPathComponent:@"test.arc”];//设置归档的文件路径 // BOOL success = [NSKeyedArchiver archiveRootObject:array toFile:path]; BOOL success=[NSKeyedArchiver archiveRootObject:array toFile:path]; if (success) { NSLog(@"archive success"); } /***解归档****/ NSArray *array2 =[NSKeyedUnarchiver unarchiveObjectWithFile:path]; NSLog(@"%@",array2);

结果： success 2013-12-28 22:14:25.353 ArchiverDemo1[1206:303] ( abc, 123, “23.4” )

2、如果是其他类型的对象存储到文件，可以利用NSKeyedArchiver类创建带键的档案来完成

NSString *homePath = NSHomeDirectory(); NSString *path = [homePath stringByAppendingPathComponent:@"archiver2.archiv"]; NSMutableData *data = [NSMutableData data]; NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data]; NSArray *array = @[@"jack",@"tom"]; [archiver encodeInt:100 forKey:@"age"]; [archiver encodeObject:array forKey:@"names"]; [archiver finishEncoding]; [archiver release]; BOOL success = [data writeToFile:path atomically:YES]; if (success) { NSLog(@"archive success"); } /***解归档对象**/ NSData *data2 = [NSData dataWithContentsOfFile:path]; NSKeyedUnarchiver *unArchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data2]; int age = [unArchiver decodeIntForKey:@"age"]; NSArray *names = [unArchiver decodeObjectForKey:@"names"]; [unArchiver release]; NSLog(@"age=%d,names=%@",age,names);

3、自定义对象进行归档，需要实现归档协议NSCoding两个方法

对属性编码，归档的时候会调用 - (void)encodeWithCoder:(NSCoder *)aCoder //对属性解码，解归档调用 - (id)initWithCoder:(NSCoder *)aDecoder

//对属性编码，归档的时候会调用 - (void)encodeWithCoder:(NSCoder *)aCoder { [aCoder encodeInt:_age forKey:AGE]; [aCoder encodeObject:_name forKey:NAME]; [aCoder encodeObject:_email forKey:EMAIL]; [aCoder encodeObject:_password forKey:PASSWORD]; } //对属性解码，解归档调用 - (id)initWithCoder:(NSCoder *)aDecoder { self = [super init]; if (self != nil) { _age = [aDecoder decodeIntForKey:AGE]; self.name = [aDecoder decodeObjectForKey:NAME]; self.email = [aDecoder decodeObjectForKey:EMAIL]; self.password = [aDecoder decodeObjectForKey:PASSWORD]; } return self; }

第三种：NSUserDefaults sample code:

[[NSUserDefaults standardUserDefaults] setObject:authData forKey:@"SinaWeiboAuthData"]; [[NSUserDefaults standardUserDefaults] synchronize];

第四种、SQlite数据库、CoreData数据库