NSCopying协议不工作

Question

我试图复制一个对象，我已经实现了NSCopying协议，它看起来像这样：

#MyActivity.h 
@interface MyActivity : MyModel <NSCopying> 
{ 
    NSInteger activityId; 
    NSInteger userId; 
    NSInteger checkinId; 
    NSString *status; 
    NSString *dateCreated; 
    NSString *dateModified; 
    NSString *dateStart; 
    NSString *dateEnd; 
    NSString *activityDescription; 
    NSString *name; 
    NSString *type; 
    NSString *repeat; 
    NSString *routineName; 
    NSString *startTimezone; 
    NSString *endTimezone; 
    GUILocation *location; 
} 

@property NSInteger activityId; 
@property NSInteger userId; 
@property NSInteger checkinId; 

@property (nonatomic, strong) NSString *status; 
@property (nonatomic, strong) NSString *dateCreated; 
@property (nonatomic, strong) NSString *dateModified; 
@property (nonatomic, strong) NSString *dateStart; 
@property (nonatomic, strong) NSString *dateEnd; 
@property (nonatomic, strong) NSString *activityDescription; 
@property (nonatomic, strong) NSString *name; 
@property (nonatomic, strong) NSString *type; 
@property (nonatomic, strong) NSString *repeat; 
@property (nonatomic, strong) NSString *routineName; 
@property (nonatomic, strong) NSString *startTimezone; 
@property (nonatomic, strong) NSString *endTimezone; 

@property (nonatomic, strong) MyLocation *location; 

-(id)copyWithZone:(NSZone *)zone; 
... 

这是我的执行文件看起来像：

#MyActivity.m 
... 
-(id)copyWithZone:(NSZone *) zone 
{ 
    GUIActivity* copyActivity  = [super copyWithZone:zone]; 
    copyActivity.activityId   = self.activityId; 
    copyActivity.userId    = self.userId; 
    copyActivity.checkinId   = self.checkinId; 
    copyActivity.status    = self.status; 
    copyActivity.dateCreated   = self.dateCreated; 
    copyActivity.dateModified  = self.dateModified; 
    copyActivity.dateStart   = self.dateStart; 
    copyActivity.dateEnd    = self.dateEnd; 
    copyActivity.activityDescription = self.activityDescription; 
    copyActivity.name    = self.name; 
    copyActivity.type    = self.type; 
    copyActivity.repeat    = self.repeat; 
    copyActivity.routineName   = self.routineName; 
    copyActivity.startTimezone  = self.startTimezone; 
    copyActivity.endTimezone   = self.endTimezone; 
    copyActivity.location   = [self.location copyWithZone:zone]; 


    return copyActivity; 
} 
... 

当我尝试通过实施该方法复制：

- (void)addActivity:(MyActivity *)activity 
      toResults:(NSMutableArray *)results 
      withDate:(NSDate *)date 
{ 
    MyActivity *actNow  = [activity copy]; 
    actNow.dateStart  = [NSDate stringFromDate:date]; 
    [results addObject:actNow]; 
} 

我仍然得到错误：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[RLMAccessor_v0_MyActivity copyWithZone:]: unrecognized selector sent to instance 0x7fe5e0c2c0a0'

类MyActivity是RLMObject一个子类，所以我不知道这有什么关系的问题。有人能指引我朝着正确的方向吗？

Answer 1

领域内部覆盖所管理属性的访问器，因此无法使其符合传统意义上的NSCopying。

如果你想上的RLMObject执行完整的深层副本，该Realm-JSON库实际上提供a way to do this：

- (instancetype)deepCopy { 
    RLMObject *object = [[NSClassFromString(self.objectSchema.className) alloc] init]; 

    for (RLMProperty *property in self.objectSchema.properties) { 

     if (property.type == RLMPropertyTypeArray) { 
      RLMArray *thisArray = [self valueForKeyPath:property.name]; 
      RLMArray *newArray = [object valueForKeyPath:property.name]; 

      for (RLMObject *currentObject in thisArray) { 
       [newArray addObject:[currentObject deepCopy]]; 
      } 

     } 
     else if (property.type == RLMPropertyTypeObject) { 
      RLMObject *value = [self valueForKeyPath:property.name]; 
      [object setValue:[value deepCopy] forKeyPath:property.name]; 
     } 
     else { 
      id value = [self valueForKeyPath:property.name]; 
      [object setValue:value forKeyPath:property.name]; 
     } 
    } 

    return object; 
}