几种数据存储方式

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:

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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：

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/***归档对象****/    NSArray *array = @[@ "abc" ,@ "123" , @23 .4];    NSString *homePath = NSHomeDirectory();    NSString *path = [homePath stringByAppendingPathComponent:@ "test.arc" ];       // 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

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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

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//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:

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1 2	[[NSUserDefaults standardUserDefaults] setObject:authData forKey:@ "SinaWeiboAuthData" ]; [[NSUserDefaults standardUserDefaults] synchronize];

第四种、SQlite数据库、CoreData数据库