对 Cloudkit 私有默认区域的查询结果是否有任何限制?我不知道为什么我只收到带有以下查询的前100条记录:
let p = NSPredicate(format: "(type == 'entered') AND (timestamp >= %@) AND (timestamp <= %@)", from, to) let q = CKQuery(recordType: self.beaconRecordType, predicate: p) q.sortDescriptors = [NSSortDescriptor(key: "timestamp", ascending: true)] self.privateDatabase?.performQuery(q, inZoneWithID: nil, completionHandler: { results, error in //count = 100 println(results.count) }
好的。正如Edwin在回答中提到的那样,解决方案是使用CKQueryOperation来获取数据的初始块,然后在completeBlock中使用“游标”来触发另一个操作。这是一个例子:
更新
func fetchBeacons(from:NSDate, to:NSDate) { let p = NSPredicate(value: true) let q = CKQuery(recordType: self.beaconRecordType, predicate: p) let queryOperation = CKQueryOperation(query: q) queryOperation.recordFetchedBlock = fetchedARecord queryOperation.queryCompletionBlock = { [weak self] (cursor : CKQueryCursor!, error : NSError!) in if cursor != nil { println("there is more data to fetch") let newOperation = CKQueryOperation(cursor: cursor) newOperation.recordFetchedBlock = self!.fetchedARecord newOperation.queryCompletionBlock = queryOperation.queryCompletionBlock self!.privateDatabase?.addOperation(newOperation) } } privateDatabase?.addOperation(queryOperation) } var i = 0 func fetchedARecord (record: CKRecord!) { println("\(NSDate().timeIntervalSinceReferenceDate*1000) \(++i)") }
标准查询的默认限制为100。该金额不是固定的。它可能会因iCloud的总负载而异。如果要影响该金额,则需要使用CKQueryOperation并按以下方式设置resultLimit:operation.resultsLimit = CKQueryOperationMaximumResults; 该CKQueryOperationMaximumResults是默认值,它将限制为100(大多数情况下)。不要将该值设置得太高。如果需要更多记录,请使用queryCompletionBlock的光标继续读取更多记录。