首先,归档和反归档的对象需要遵从coding协议
@interface YCBreakDownModel : NSObject<NSCoding>

然后支持归档需要实现方法:
- (void)encodeWithCoder:(NSCoder *)aCoder
反归档需要实现:
- (instancetype)initWithCoder:(NSCoder *)aDecoder

利用runtime, class_copyIvarList函数, 取得ivar指向成员变量的指针,利用ivar_getName函数,取得属性名,利用kvc取得属性值

代码

- (void)encodeWithCoder:(NSCoder *)aCoder {
    unsigned int propertyCount;
    Ivar * ivars = class_copyIvarList([self class], &propertyCount);
    for (int i = 0; i < propertyCount; i ++) {
        Ivar ivar = ivars[i];
        NSString * key = [NSString stringWithUTF8String:ivar_getName(ivar)];
        [aCoder encodeObject:[self valueForKey:key] forKey:key];
    }
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    if (self = [super init]) {
        unsigned int propertyCount;
        Ivar * ivars = class_copyIvarList([self class], &propertyCount);
        for (int i = 0; i < outCount; i ++) {
            Ivar ivar = ivars[i];
            NSString * key = [NSString stringWithUTF8String:ivar_getName(ivar)];
            [self setValue:[aDecoder decodeObjectForKey:key] forKey:key];
        }
    }
    return self;
}