NSSortDescriptor on distanceToLocation No？

Question

使用CloudKit CKQuery，您可以在距离上进行筛选(参见示例)。但是你怎么能在距离上排序呢？就像位置ASC。位置上的排序描述符返回一个错误：query.sortDescriptors = [NSSortDescriptor(key: "distanceToLocation", ascending: true)]：

  static func getNearbySpots(location : CLLocation, completionHandler: (spots : CKRecord[]) -> Void) {
        let predicate = NSPredicate(format: "distanceToLocation:fromLocation:(location, %@) < 10000", location)

        let queryOperation = CKQueryOperation(query: query)
        var results : CKRecord[] = []

        queryOperation.recordFetchedBlock = {
            results += $0
        }

        queryOperation.queryCompletionBlock = {
            if $1 {
                NSLog($1.description,[])
                abort()
            } else {
                completionHandler(spots: results)
            }
        }

        self.publicDB().addOperation(queryOperation)
    }

Answer 1

好了找到了。有一个CKLocationSortDescriptor，您可以在这里指定位置。

 query.sortDescriptors = [CKLocationSortDescriptor(key: "location", relativeLocation: location)]