Objective c PFQuery findObjectsInBackground返回nil。为什么？

如果我使用

[query includeKey@“someKey”]

方法

[query findObjectsInBackground]

返回

nil

，当我不使用includeKey时，findObjectsInBackground返回按键数组@“someKey”的对象，但此数组返回空对象

代码示例

    PFQuery *query = [PFQuery queryWithClassName:@"PrimaryCategory"];
    //[query includeKey:@"primaryIncomesCategories"];
    [query fromLocalDatastore];

    [query findObjectsInBackgroundWithBlock:^(NSArray *PF_NULLABLE_S objects, NSError *PF_NULLABLE_S error)
     {
         if (!error && objects.count)
         {
             self.primaryIncomesCategories = [self convertPFObjectToFBAPFCategory:objects.firstObject[@"primaryIncomesCategories"]];
         }

         if(completion)
             completion();
     }];
}

   primaryIncomesCategories =     (
    "<p><Category: 0x796f8dd0, objectId: eLiQQ0OCxV, localId: (null)> {\n}",
etc

在日志中

    PFQuery *query = [PFQuery queryWithClassName:@"PrimaryCategory"];
    //[query includeKey:@"primaryIncomesCategories"];
    [query fromLocalDatastore];

    [query findObjectsInBackgroundWithBlock:^(NSArray *PF_NULLABLE_S objects, NSError *PF_NULLABLE_S error)
     {
         if (!error && objects.count)
         {
             self.primaryIncomesCategories = [self convertPFObjectToFBAPFCategory:objects.firstObject[@"primaryIncomesCategories"]];
         }

         if(completion)
             completion();
     }];
}

   primaryIncomesCategories =     (
    "<p><Category: 0x796f8dd0, objectId: eLiQQ0OCxV, localId: (null)> {\n}",
etc

我用这种方法储蓄

    [primaryCategory setObject:incomeCategoryArray forKey:@"primaryIncomesCategories"];
    [primaryCategory pinInBackground];

incomeCategory数组

是否为

非零

结束此数组中的对象

非空。