nspredicate - How can I get NSManagedObject from NSExpression?

Question

I have this predicate:

DG == <DG: 0x8c8dbd0> (entity: DG; id: 0x8c91140 <x-coredata://5F7ECBA0-D9B4-489A-85DA-3BE10A8D65CB-94947-00026842BC158909/DG/p2> ; data: <fault>)

How can I restore NSManagedObject from comparisonPredicate.rightExpression.constantValue

Answer 1

我的解决方案是解决我自己的问题，而不是使用这种谓词：@"DG == %@"，我现在使用：@"DG.objectID == %@"，当然参数不是 NSManagedObject 而是 NSManagedObjectID。