ios - 使用 arc 和 dynamic 属性覆盖 setter

Question

我需要在 setter 方法中做一些额外的事情。但是这样做时我得到了一个无限循环:

我有一个核心数据对象

@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，在这种情况下，我得到了一个无限循环。好的，所以我在网上搜索并按以下方式修改了我的代码，对于每个版本我都会遇到编译器错误

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
}

现在，我问自己如何做到这一点？

Answer 1

我的问题的解决方案:

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

@implementation Transaction
@dynamic date;

-(void)setDate:(NSDate *)date
{
    [self setPrimitiveValue:date forKey:@"date"];
    //additional stuff omitted
}