如何在使用Core Data时覆盖属性上的getter？ [英] How can I override a getter on a property when using Core Data?

问题描述

我想能够覆盖我的一个核心数据模型上的字符串属性的getter，我需要找到该属性的值。

  @interface LabTest：NSManagedObject {
} 
 @property（nonatomic，retain）NSString * status; 
 @end 
 
 @implementation LabTest 
 
 @dynamic状态; 
 
  - （NSString *）status {
 NSString * tempStatus = [super valueForKey：@status]; 
 //做一些检查这里
 return tempStatus; 
} 
 
 @end 
  

上述代码。我尝试了几个不同的东西，但我认为他们都结束了一个无限循环与程序崩溃的代码139。

什么是正确的方法

[self primitiveValueForKey：@ status] 而不是 [super valueForkey：@status] ？

I want to be able to override the getter on a string property on one of my core data models and inside the getter I need to find out what the value is for that property.

@interface LabTest : NSManagedObject {
}
@property (nonatomic, retain) NSString *status;
@end

@implementation LabTest

@dynamic status;

- (NSString *)status {
    NSString *tempStatus = [super valueForKey:@"status"];
    //do some checking here
    return tempStatus;
}

@end

The code above crashes the process. I have tried a few different things, but I think they all end up in an infinite loop with the program crashing with a code of 139.

What is the correct way to access a core data member in the getter like this?

解决方案

Have you tried [self primitiveValueForKey:@"status"] instead of [super valueForkey:@"status"]?

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