您好，对于分配给完成 block 内的外部 ref 变量的值的范围是什么感到困惑。例如，在下面的代码中，操作错误和保存记录的值将在完成 block 之外保留。
func applyLocalChangesToServer(insertedOrUpdatedCKRecords:Array<CKRecord>,deletedCKRecordIDs:Array<CKRecordID>) throws
{
var savedRecords:[CKRecord]?
var conflictedRecords:[CKRecord] = [CKRecord]()
var removeRecords:[CKRecord] = [CKRecord]()
var operationError : NSError?
let ckModifyRecordsOperation = CKModifyRecordsOperation(recordsToSave:insertedOrUpdatedCKRecords, recordIDsToDelete: deletedCKRecordIDs);
ckModifyRecordsOperation.atomic = true
ckModifyRecordsOperation.modifyRecordsCompletionBlock = ({(savedRecords1,deletedRecordIDs1,error)->Void in
operationError = error
if error == nil
{
wasSuccessful = true
savedRecords = savedRecords1
}
else
{
wasSuccessful = false
savedRecords = nil
errorCKS = self.handleError(error!)
}
})
ckModifyRecordsOperation.perRecordCompletionBlock = ({(ckRecord,error)->Void in
if error != nil
{
if error!.code == CKErrorCode.ServerRecordChanged.rawValue
{
conflictedRecords.append(ckRecord!)
}
}
})
self.operationQueue?.addOperation(ckModifyRecordsOperation)
self.operationQueue?.waitUntilAllOperationsAreFinished()
if conflictedRecords.count > 0
{
//Do work here
}
else if operationError != nil //Other then the partial error
{
throw operationError
}
}
注意:有分配操作错误，因为 func applyLocalChangesToServer 抛出错误并且位于 while 循环内。
最佳答案
您的假设是正确的，在执行完成处理程序后，这些在封装范围内定义的变量将被修改。所以您的代码应该按预期工作。
您还可以使用以下内容:
ckModifyRecordsOperation.main()
而不是:
self.operationQueue?.addOperation(ckModifyRecordsOperation)
self.operationQueue?.waitUntilAllOperationsAreFinished()
希望有帮助。
关于ios - 其值在 block 内赋值的引用变量，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37538300/