用弧和動態屬性覆蓋setter

Question

我需要在setter方法中做一些額外的東西。但我這樣做的時候所以得到一個無限循環：

我有一個核心的數據對象

@interface Transaction : NSManagedObject 
@property (nonatomic, retain) NSDate * date; 
@end 

@implementation Transaction 
@dynamic date; 

-(void)setDate:(NSDate *)date 
{ 
    self.date = date; 
    //additional stuff omitted 
} 

所以，在這種情況下，我得到一個無限循環。好了，所以我在網上搜索，並以下列方式修改我的代碼，併爲每一個版本，我得到編譯器錯誤

版本1：

@interface Transaction : NSManagedObject 
@property (nonatomic, retain) NSDate * date; 
@end 

@implementation Transaction 
@dynamic date; 

-(void)setDate:(NSDate *)date 
{ 
    self->date = date; //Error: Property 'date' found on object 'Transaction *'; did you mean to access it with the "." operator? 
    //additional stuff omitted 
} 

版本2：

@interface Transaction : NSManagedObject 
@property (nonatomic, retain) NSDate * date; 
@end 

@implementation Transaction 
@dynamic date = _date; //Error: Expected ';' after @dynamic 

-(void)setDate:(NSDate *)date 
{ 
    _date = date; 
    //additional stuff omitted 
} 

現在，我我在問自己該怎麼做？

Answer 1

的解決方案，我問題：

​​

Answer 2

「日期」是否由核心數據中的相應屬性支持？

如果是的話，請看看Custom setter methods in Core-Data

如果沒有，你不需要堅持「日期」，你的代碼應該是以下幾點：

@interface Transaction : NSManagedObject 
@property (nonatomic, retain) NSDate * date; 
@end 

@implementation Transaction 
@synthesize date = _date; 

-(void)setDate:(NSDate *)date 
{ 
    _date = date; 
    //additional stuff omitted 
} 

Answer 3

下面是壓倒一切的NSManagedObject性質沒有打破國際志願者組織，在您的m的新方法：

@interface Transaction(DynamicAccessors) 
- (void)managedObjectOriginal_setDate:(NSDate *)date; 
@end 

@implementation Transaction 
@dynamic date; 

- (void)setDate:(NSDate *)date 
{ 
    // invoke the dynamic implementation of setDate 
    [self managedObjectOriginal_setDate:(NSString *)date; 
    // your custom code 
} 

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