ios – CKRecord获得密钥的价值

class func getByUsername(username: String,callBACk: (records: [CKRecord]) -> ()){
    getSumMary(NSPreDicate(format: "Username == %@",userName)){(records: [CKRecord]) -> Void in
        callBACk(records: records)
    }
}

class func getSumMary(preDicate: NSPreDicate,callBACk: (records: [CKRecord]) -> ()){
    let query = CKQuery(recordType: "UserInfo",preDicate: preDicatE)
    let queryOperation = CKQueryOperation(query: query)
    queryOperation.desiredKeys = ["ID"]

    var records = [CKRecord]()
    queryOperation.recordFetchedBlock = {record in records.append(record)}
    queryOperation.queryCompletionBlock = {_ in callBACk(records: records)}

    CKContainer.defaultContainer().publicCloudDatabase.addoperation(queryOperation)
}

然后我可以通过以下方式获得正确的记录：

getByUsername("Username"){(records: [CKRecord]) -> Void in
  var record: CKRecord = records[0]
}

我也可以通过使用获得正确的ID

var id: String = record.recordID.recordName

所以我知道我正在获取正确的记录,但是,当我尝试从记录中获取值时,例如用户的电子邮件,则返回nil：

var email: String = record.objectForKey("Email") as String

我也尝试过：

record.valueForKey("Email")
record.valueForKeyPath("Email")

当我打印record.allKeys()时,我得到一个空数组,[],当我打印record.allTokens()时,我得到一个nil的返回

我没有正确地从记录中获取值,或者我是否必须在数据库中查询我希望使用记录ID获取的每个值？基于the documentation所说的：

我假设我不必查询数据库中我想获得的每个值,并且从iCloud获取值时,这些值会自动插入到CKRecord中