不用runtime，直接kvc
添加初始化方法
- (instancetype)initWithDictionary:(NSDictionary*)dictionary{
self = [super init];
if (self) {
[self setValuesForKeysWithDictionary:dictionary];
}
return self;
}
重写
- (void)setValue:(id)value forUndefinedKey:(NSString *)key
爽~~
