Swift 使用新游标多次执行CKQueryOperation
我有一个CKQueryOperation,处理了上千条记录,因此我需要多次执行该操作。我尝试更改光标并添加如下代码中的操作:Swift 使用新游标多次执行CKQueryOperation,swift,cloudkit,ckquery,Swift,Cloudkit,Ckquery,我有一个CKQueryOperation,处理了上千条记录,因此我需要多次执行该操作。我尝试更改光标并添加如下代码中的操作: let queryOperation = CKQueryOperation(query: query) queryOperation.recordFetchedBlock = { (rule: CKRecord) in print(rule) } queryOperation.database = publicDB queryOperation.query
let queryOperation = CKQueryOperation(query: query)
queryOperation.recordFetchedBlock = { (rule: CKRecord) in
print(rule)
}
queryOperation.database = publicDB
queryOperation.queryCompletionBlock = { (cursor : CKQueryCursor?, error : NSError?) in
if error != nil {
print(error?.localizedFailureReason)
} else {
if cursor != nil { // The cursor is not nil thus we still have some records to download
queryOperation.cursor = cursor
queue.addOperation(queryOperation)
} else {
print("Done")
}
}
}
// Creation of the dependent operation secondQueryOperation
queue.addOperations([queryOperation, secondQueryOperation], waitUntilFinished: true)
运行时,它崩溃并返回[NSOperationQueue addOperation:]:操作正在执行,无法排队。我能做什么?在此之后,我还有其他依赖于此查询操作的操作,因此我需要在开始其他操作之前正确完成hit。您应该创建一个新的操作,而不是在其他时间执行相同的操作。下面您可以从中看到一段代码片段,以了解如何使用它
internal func queryRecords<T:EVCloudKitDataObject>(type:T, query: CKQuery, completionHandler: (results: [T]) -> Bool, errorHandler:((error: NSError) -> Void)? = nil) {
if !(query.sortDescriptors != nil) {
query.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
}
let operation = CKQueryOperation(query: query)
var results = [T]()
operation.recordFetchedBlock = { record in
if let parsed = self.fromCKRecord(record) as? T {
results.append(parsed)
}
}
operation.queryCompletionBlock = { cursor, error in
self.handleCallback(error, errorHandler: errorHandler, completionHandler: {
if completionHandler(results: results) {
if cursor != nil {
self.queryRecords(cursor!, continueWithResults: results, completionHandler: completionHandler, errorHandler: errorHandler)
}
}
})
}
operation.resultsLimit = CKQueryOperationMaximumResults;
database.addOperation(operation)
}
private func queryRecords<T:EVCloudKitDataObject>(cursor: CKQueryCursor, continueWithResults:[T], completionHandler: (results: [T]) -> Bool, errorHandler:((error: NSError) -> Void)? = nil) {
var results = continueWithResults
let operation = CKQueryOperation(cursor: cursor)
operation.recordFetchedBlock = { record in
if let parsed = self.fromCKRecord(record) as? T {
results.append(parsed)
}
}
operation.queryCompletionBlock = { cursor, error in
self.handleCallback(error, errorHandler: errorHandler, completionHandler: {
if completionHandler(results: results) {
if cursor != nil {
self.queryRecords(cursor!, continueWithResults: results, completionHandler: completionHandler, errorHandler: errorHandler)
}
}
})
}
operation.resultsLimit = CKQueryOperationMaximumResults;
database.addOperation(operation)
}
如何初始化secondQueryOperation?NSQueryOperation的正常初始化,然后是secondQueryOperation.AddDependencyQueryOperation只是一个小建议,请检查!results.isEmpty,然后使用光标安排下一个操作。当resultsLimit恰好小于记录数时,有时甚至在获取所有记录之后也会返回游标。我认为这是CloudKit的一个bug,最好检查一下!results.isEmpty,这样我们就不会无限期地继续查询