归档(NSCoding)--->持久化存储

作为持久化存储的一种,  NSKeyedArchiver - 对象归档

1.首先要先继承NSCoding协议.

2.实现归档和解归档的两个方法如下:

/**编码的方法,将数据编码成可以写入本地的状态*/
- (void)encodeWithCoder:(NSCoder *)aCoder;
/**解码方法,从本地读取数据,重新创建对象进行初始化*/
- (instancetype)initWithCoder:(NSCoder *)aDecoder;

3.存储:(可以从服务器上直接获取一个字典存储,也可以存储到沙盒中读取).

/**从服务器上获取*/
+ (User *)getUserLoginSuccessInfoDic:(NSDictionary *)infoDic;
/**存储到沙盒中*/
NSKeyedUnarchiver 从二进制流读取对象。
[NSKeyedArchiver archiveRootObject:stu toFile:path]; 存储 

 4.读取

NSKeyedUnarchiver unarchiveObjectWithFile:path

 5.具体例子:

5.1沙盒

5.11 存储

 // 1.新的模型对象  
    User *user = [[User alloc] init];  
    user.name = @"星仔";  
    user.age = 18;  
    user.height = 1.85;  
      
    // 2.归档模型对象  
    // 2.1.获得Documents的全路径  
    NSString *doc = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];  
    // 2.2.获得文件的全路径  
    NSString *path = [doc stringByAppendingPathComponent:@"user.data"];  
    // 2.3.将对象归档  
    [NSKeyedArchiver archiveRootObject:stu toFile:path];  

5.12 读取

  // 1.获得Documents的全路径  
    NSString *doc = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];  
    // 2.获得文件的全路径  
    NSString *path = [doc stringByAppendingPathComponent:@"user.data"];  
      
    // 3.从文件中读取MJStudent对象  
    MJStudent *stu = [NSKeyedUnarchiver unarchiveObjectWithFile:path];  

5.13实现归档与解档方法

/** 
 *  将某个对象写入文件时会调用 
 *  在这个方法中说清楚哪些属性需要存储 
 */  
- (void)encodeWithCoder:(NSCoder *)encoder  
{  
    [encoder encodeObject:self.name forKey:@"name"];  
    [encoder encodeInt:self.age forKey:@"age"];  
    [encoder encodeDouble:self.height forKey:@"height"];  
}  
  
/** 
 *  从文件中解析对象时会调用 
 *  在这个方法中说清楚哪些属性需要存储 
 */  
- (id)initWithCoder:(NSCoder *)decoder  
{  
    if (self = [super init]) {  
        // 读取文件的内容  
        self.no = [decoder decodeObjectForKey:@"name"];  
        self.age = [decoder decodeIntForKey:@"age"];  
        self.height = [decoder decodeDoubleForKey:@"height"];  
    }  
    return self;  
} 

 

5.2从服务器上获取

/**从服务器上获取*/
+ (User *)getUserLoginSuccessInfoDic:(NSDictionary *)infoDic {
    
    if (infoDic == nil ||(NSNull *)infoDic == [NSNull null])
        return nil;
    
    User *loginUser = [[User alloc] init];
    loginUser.UUID = [infoDic objectForKey:@"UUID"];
    NSDictionary *userInfoDic = [infoDic objectForKey:@"user"];
    if (userInfoDic) {
        loginUser.ID = [[userInfoDic objectForKey:@"id"] integerValue];
        loginUser.contactsname = [userInfoDic objectForKey:@"contactsname"];
        loginUser.contactsmail = [userInfoDic objectForKey:@"contactsmail"];
        loginUser.contactsphone = [userInfoDic objectForKey:@"contactsphone"];
        loginUser.headportrait = [userInfoDic objectForKey:@"headportrait"];
    }else{
  
        loginUser.contactsname = @"";
        loginUser.contactsmail = @"";
        loginUser.contactsphone = @"";
    }
    
    return loginUser;
}

5.21.实现归档和解归档方法

/**归档*/
- (void)encodeWithCoder:(NSCoder *)aCoder{
    [aCoder encodeObject:self.UUID forKey:@"l_uuid"];
    [aCoder encodeInteger:self.ID forKey:@"l_id"];
    [aCoder encodeObject:self.contactsname forKey:@"l_contactsname"];
    [aCoder encodeObject:self.contactsmail forKey:@"l_contactsmail"];
    [aCoder encodeObject:self.contactsphone forKey:@"l_contactsphone"];
    [aCoder encodeObject:self.headportrait forKey:@"l_headportrait"];
    
}
/**解档*/
- (instancetype)initWithCoder:(NSCoder *)aDecoder{
    if (self = [super init]) {
        
        self.UUID = [aDecoder decodeObjectForKey:@"l_uuid"];
        self.ID = [aDecoder decodeIntegerForKey:@"l_id"];
        self.contactsname = [aDecoder decodeObjectForKey:@"l_contactsname"];
        self.contactsmail = [aDecoder decodeObjectForKey:@"l_contactsmail"];
        self.contactsphone = [aDecoder decodeObjectForKey:@"l_contactsphone"];
        self.headportrait = [aDecoder decodeObjectForKey:@"l_headportrait"];
    }
    return self;
}