我正在尝试使用CloudKit和光标从我的iCloud公共数据库下载一批记录.无论resultLimit如何设置,代码都可以在前3次执行中正常工作,但是从不执行第4个完成块.如果没有设置resultsLimit,我会得到300条记录,如果它设置为50,我会得到150,如果它设置为5,我得到15 …
没有报告错误,并且该块似乎已添加,但从未执行过.平台是OS X.这是有问题的代码：
let queryOp = CKQueryOperation(query: query)
queryOp.recordFetchedBlock = self.fetchedDetailRecord
queryOp.resultsLimit = 5
queryOp.queryCompletionBlock = { [weak self]
(cursor: CKQueryCursor!,error: NSError!) -> Void in
println("comp block called with \(cursor) \(error)")
if error != nil {
println("Error on fetch \(error.userInfo)")
} else {
if cursor != nil {
let nextOp = CKQueryOperation(cursor: cursor)
nextOp.recordFetchedBlock = self!.fetchedDetailRecord
nextOp.queryCompletionBlock = queryOp.queryCompletionBlock
nextOp.resultsLimit = 5
self!.publicDatabase?.addOperation(nextOp)
println("added next fetch")
} else {
self!.fileHandle!.closeFile()
self!.exportProgressIndicator.stopAnimation(self)
}
}
}
self.publicDatabase?.addOperation(queryOp)
这是控制台的结果 –
459013587628.012 0
459013587628.621 1
459013587628.863 2
459013587629.113 3
459013587629.339 4
使用nil调用comp块
添加了下一个提取
459013587828.552 5
459013587828.954 6
459013587829.198 7
459013587829.421 8
459013587829.611 9
使用nil调用comp块
添加了下一个提取
459013587997.084 10
459013587997.479 11
459013587997.74 12
459013587997.98 13
459013587998.207 14
大数字只是对recordFetchedBlock的调用之间的时间,第二个数字是调用该块的次数.
我很难过……关于如何进行的任何想法？哦,container和publicDatabase是类变量,并在运行上面的代码片段之前进行了初始化.
您在queryCompletionBlock范围内定义nextOp的方式在该块的三次迭代后导致问题.如果你将CKQueryOperation的创建分解为自己的方法,你的问题就会消失.
这是代码：
func fetchedDetailRecord(record: CKRecord!) -> Void {
println("Retrieved record: \(record)")
}
func createQueryOperation(cursor: CKQueryCursor? = nil) -> CKQueryOperation {
var operation:CKQueryOperation
if (cursor != nil) {
operation = CKQueryOperation(cursor: cursor!)
} else {
operation = CKQueryOperation(query: CKQuery(...))
}
operation.recordFetchedBlock = self.fetchedDetailRecord
operation.resultsLimit = 5
operation.queryCompletionBlock = { [weak self]
(cursor: CKQueryCursor!,error: NSError!) -> Void in
println("comp block called with \(cursor) \(error)")
if error != nil {
println("Error on fetch \(error.userInfo)")
} else {
if cursor != nil {
self!.publicDatabase?.addOperation(self!.createQueryOperation(cursor: cursor))
println("added next fetch")
} else {
self!.fileHandle!.closeFile()
self!.exportProgressIndicator.stopAnimation(self)
}
}
}
return operation
}
func doQuery() {
println("Querying records...")
self.publicDatabase?.addOperation(createQueryOperation())
}
