[英]Swift 4 CloudKit queryCompletionBlock doesn't appear to execute
I followed several CKQueryOperation examples/narratives on problems to fetch from CloudKit. 我遵循了几个有关从CloudKit中获取问题的CKQueryOperation示例/说明。 My table has about 370 rows and 8 columns..at best I can only fetch about 60 rows. 我的表有大约370行和8列。.充其量我只能获取大约60行。 resultsLimit parameter does not seem to help.. My queryCompletionBlock is not executing. resultsLimit参数似乎没有帮助。我的queryCompletionBlock没有执行。 Sometimes I fetch 5 rows and other time 30+ Response from Cloud is quick just now all rows It's got to be some newbie code mistake! 有时我获取5行,其他时间获取30+的云,所有行现在的响应很快,这一定是一些新手代码错误!
func getData() {
let predicate = NSPredicate(value: true)
let query = CKQuery(recordType: RemoteFunctions.RemoteRecords.booksDB, predicate: predicate)
let cloudContainer = CKContainer.default()
let privateDatabase = cloudContainer.privateCloudDatabase
let operation = CKQueryOperation(query: query)
operation.queuePriority = .veryHigh
operation.resultsLimit = 20
operation.recordFetchedBlock = { (record: CKRecord) in
self.allRecords.append(record)
print(record)
}
operation.queryCompletionBlock = {[weak self] (cursor: CKQueryCursor?, error: NSError?) in
// There is another batch of records to be fetched
print("completion block called with \(String(describing: cursor))")
if let cursor = cursor {
let newOperation = CKQueryOperation(cursor: cursor)
newOperation.recordFetchedBlock = operation.recordFetchedBlock
newOperation.queryCompletionBlock = operation.queryCompletionBlock
newOperation.resultsLimit = 10
privateDatabase.add(newOperation)
print("more records")
}
// There was an error
else if let error = error {
print("Error:", error)
}
// No error and no cursor means the operation was successful
else {
print("Finished with records:")
}
} as? (CKQueryCursor?, Error?) -> Void
// privateDatabase.add(operation) // privateDatabase.add(operation)
}
Remove the as? (CKQueryCursor?, Error?) -> Void
删除as? (CKQueryCursor?, Error?) -> Void
as? (CKQueryCursor?, Error?) -> Void
near the end. as? (CKQueryCursor?, Error?) -> Void
在尽头。 Be careful not to remove the preceeding brace. 注意不要卸下前面的支架。
Remove newOperation.resultsLimit = 10
in your cursor block. 在游标块中删除newOperation.resultsLimit = 10
。
Add operation = newOperation
immediately above privateDatabase.add(newOperation)
在privateDatabase.add(newOperation)
正上方添加operation = newOperation
Uncomment the privateDatabase.add(operation)
取消注释privateDatabase.add(operation)
That should help. 那应该有帮助。 Large fetches, where the cursor block gets hit more than 3 times can be problematic. 较大的访存会导致光标块被命中3次以上的情况。 If you do the above, you should be ok. 如果执行上述操作,应该没问题。 Some people like to write/call the cursor block as its own function. 有些人喜欢将游标块作为其自身的功能来编写/调用。 That works as well, but it isn't necessary. 效果也不错,但这不是必需的。
You could try this... 你可以试试这个...
func getData(withCursor cursor: CKQueryCursor? = nil)
{
let cloudContainer = CKContainer.default()
let privateDatabase = cloudContainer.privateCloudDatabase
let operation: CKQueryOperation
if let cursor = cursor
{
operation = CKQueryOperation(cursor: cursor)
}
else
{
let operation_configuration: CKOperationConfiguration = CKOperationConfiguration()
operation_configuration.isLongLived = true
operation_configuration.qualityOfService = .background
let predicate = NSPredicate(value: true)
let query = CKQuery(recordType: RemoteFunctions.RemoteRecords.booksDB, predicate: predicate)
operation = CKQueryOperation(query: query)
operation.queuePriority = .veryHigh
operation.configuration = operation_configuration
operation.recordFetchedBlock = { (record: CKRecord) in
self.allRecords.append(record)
print(record)
}
operation.queryCompletionBlock = {[weak self] (cursor: CKQueryCursor?, error: NSError?) in
// There is another batch of records to be fetched
print("completion block called with \(String(describing: cursor))")
if let error = error
{
print("Error:", error)
}
else if let cursor = cursor
{
self.getData(withCursor: cursor)
}
else
{
print("Finished with records:")
}
}
}
privateDatabase.add(operation)
}
This is a recursive version of your fuction, using the new CKQueryOperation
API. 使用新的CKQueryOperation
API,这是功能的递归版本。
It seems that your're loosing reference to the operation object when a cursor arrives. 似乎当光标到达时,您正在丢失对操作对象的引用。
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