objective-c - NSManagedObjectIDs 数组，一次获取对象

Question

我有一个 NSManagedObjectID 数组。有没有比遍历数组并单独获取它们更有效的方法来获取关联的托管对象？

Answer 1

使用以下谓词执行fetchRequest

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"self in %@", arrayOfIds];

完整示例

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
fetchRequest.entity = myEntityDescription;

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"self in %@", arrayOfIds];

fetchRequest.predicate = predicate;
fetchRequest.sortDescriptors = mySortDescriptors;

NSError *error = nil;
NSArray *managedObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];
[fetchRequest release]; fetchRequest = nil;