歸檔也叫序列化，是將文件存在硬盤，解檔是從硬盤還原

5種方式：

第一種、使用屬性列表進行歸檔

如果對象是NSString，NSDictionary,NSArray,NSData或者NSNumber，可以使用writeToFile:atomically方法將數據寫到文件,注意這種方式是明文

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--對象歸檔，數據會加密

1、對於NSArray或者NSDictionary sample code：

        /***歸檔對象****/
        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");
        }
        
        /***解歸檔****/
        NSArray *array2 =[NSKeyedUnarchiver unarchiveObjectWithFile:path];
      NSLog(@"%@",array2);

結果：

success

2013-12-28 22:14:25.353 ArchiverDemo1[1206:303] (

abc,

123,

"23.4"

)

2、如果是其他類型的對象存儲到文件，可以利用NSKeyedArchiver類創建帶鍵的檔案來完成

        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");
        }
        
        /***解歸檔對象**/

        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、自定義對象進行歸檔，需要實現歸檔協議NSCoding兩個方法

對屬性編碼，歸檔的時候會調用

- (void)encodeWithCoder:(NSCoder *)aCoder

//對屬性解碼，解歸檔調用

- (id)initWithCoder:(NSCoder *)aDecoder

//對屬性編碼，歸檔的時候會調用
- (void)encodeWithCoder:(NSCoder *)aCoder {
    [aCoder encodeInt:_age forKey:AGE];
    [aCoder encodeObject:_name forKey:NAME];
    [aCoder encodeObject:_email forKey:EMAIL];
    [aCoder encodeObject:_password forKey:PASSWORD];
    
}

//對屬性解碼，解歸檔調用
- (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;
}

第三種：NSUserDefaults

sample code:

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

第四種、SQlite數據庫、CoreData數據庫