我有一个如下所示的Objective-C类:@interfaceCustomObjectHavingData:NSObject@property(nonatomic,strong)NSData*objWithData;-(instancetype)initWithObjHavingData;@end和这样的实现@implementationCustomObjectHavingData-(instancetype)initWithObjHavingData{if(self=[superinit]){NSString*str=@"Thisissimplestring.";self.objW