我正在尝试更新我的核心数据堆栈中的现有对象，正在检索对象并且我可以更改值，但是在保存上下文时，没有保存任何内容。也是hasChangesNO并且updatedObjects是空的。
NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName: @"MyModel"];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(x == %@) AND (y == %@)", x, y];
request.returnsObjectsAsFaults = NO;
request.predicate = predicate;
NSArray *results = [self.managedObjectContext executeFetchRequest: request error: nil];
MyModel *model = results[0];
model.newvalue = "somenewvalue";
NSLog(@"%@", (self.managedObjectContext.hasChanges)?@"YES":@"NO"); // -> Shows NO
NSLog(@"%@", self.managedObjectContext.updatedObjects); // -> Shows empty array
[self saveContext]; // No error, seems to be working successfully but the updated objects is empty as well has "hasChanges", so something else is being missed here
这有点令人费解和烦人。我真的很感激关于这个问题的任何见解。
正如建议的那样，这也被尝试过，但没有帮助
NSManagedObject *model = results[0];
[model setValue: @"somenewvalue" forKey: @"newvalue"];