如何通過NSCoding和NSSecureCoding進(jìn)行對(duì)象序列化

NSCoding和NSSecureCoding都是Objective-C中用于對(duì)象序列化和反序列化的協(xié)議，可以通過實(shí)現(xiàn)這兩個(gè)協(xié)議來對(duì)對(duì)象進(jìn)行序列化。

要實(shí)現(xiàn)NSCoding協(xié)議，首先需要在對(duì)象中實(shí)現(xiàn)兩個(gè)方法：- (void)encodeWithCoder:(NSCoder *)aCoder和- (instancetype)initWithCoder:(NSCoder *)aDecoder。在encodeWithCoder方法中，將對(duì)象的屬性編碼到aCoder中；在initWithCoder方法中，從aDecoder中解碼出屬性值。

示例代碼如下：

@interface Person : NSObject <NSCoding>

@property (nonatomic, strong) NSString *name;
@property (nonatomic, assign) NSInteger age;

@end

@implementation Person

- (void)encodeWithCoder:(NSCoder *)aCoder {
    [aCoder encodeObject:self.name forKey:@"name"];
    [aCoder encodeInteger:self.age forKey:@"age"];
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super init];
    if (self) {
        self.name = [aDecoder decodeObjectForKey:@"name"];
        self.age = [aDecoder decodeIntegerForKey:@"age"];
    }
    return self;
}

@end

要實(shí)現(xiàn)NSSecureCoding協(xié)議，需要在對(duì)象中實(shí)現(xiàn)一個(gè)類方法+ (BOOL)supportsSecureCoding，在這個(gè)方法中返回YES表示該對(duì)象支持安全編碼。

示例代碼如下：

@interface Person : NSObject <NSSecureCoding>

@property (nonatomic, strong) NSString *name;
@property (nonatomic, assign) NSInteger age;

@end

@implementation Person

+ (BOOL)supportsSecureCoding {
    return YES;
}

- (void)encodeWithCoder:(NSCoder *)aCoder {
    [aCoder encodeObject:self.name forKey:@"name"];
    [aCoder encodeInteger:self.age forKey:@"age"];
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super init];
    if (self) {
        self.name = [aDecoder decodeObjectForKey:@"name"];
        self.age = [aDecoder decodeIntegerForKey:@"age"];
    }
    return self;
}

@end

通過實(shí)現(xiàn)NSCoding和NSSecureCoding協(xié)議，可以將對(duì)象序列化為NSData，然后可以將NSData保存到文件或者傳輸給其他系統(tǒng)。