NSCoding

• 簡介
  NSCoding是把數(shù)據(jù)存儲在iOS和Mac OS上的一種極其簡單和方便的方式，它把模型對象直接轉(zhuǎn)變成一個文件，然后再把這個文件重新加載到內(nèi)存里，并不需要任何文件解析和序列化的邏輯。
• 使用
  對象需要實現(xiàn)了NSCoding協(xié)議

// 存儲
Teacher *t = [[Teacher alloc] init];
t.name = [NSMutableString stringWithString: @"李剛"];
t.age = 40;
t.className = @"English";

[NSKeyedArchiver archiveRootObject:t toFile:_file];

// 讀取
Teacher *t = [NSKeyedUnarchiver unarchiveObjectWithFile:_file];

• 實現(xiàn)NSCoding協(xié)議
  需要實現(xiàn)兩個方法
  - (void)encodeWithCoder:(NSCoder *)aCoder;
- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder;

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super init];
    if (self) {
        self.name = [aDecoder decodeObjectOfClass:[NSMutableString class] forKey:NSStringFromSelector(@selector(name))];
        self.age = [[aDecoder decodeObjectOfClass:[NSNumber class] forKey:NSStringFromSelector(@selector(age))] unsignedIntegerValue];
        self.className = [aDecoder decodeObjectOfClass:[NSString class] forKey:NSStringFromSelector(@selector(className))];
    }
    return self;
}

- (void)encodeWithCoder:(NSCoder *)aCoder {
    [aCoder encodeObject:self.name forKey:NSStringFromSelector(@selector(name))];
    [aCoder encodeObject:[NSNumber numberWithUnsignedInteger:self.age] forKey:NSStringFromSelector(@selector(age))];
    [aCoder encodeObject:self.className forKey:NSStringFromSelector(@selector(className))];
}

NSSecureCoding

• 簡介
  NSSecureCoding是NSCoding的變種，因為NSCoding畢竟不太安全，大部分支持NSCoding的系統(tǒng)對象都已經(jīng)升級到支持NSSecureCoding了，如AFNetworking的AFURLSessionManager。

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