问题
I'm doing the sync to mirror a sqlite DB to a server one.
I have a Master-Detail table, where the details must be send to the server ASAP. However, is possible that detail 3 arrive before detail 2. I need to mimic the steps made to the document and respect the order of the operations.
When a record is saved locally, I send a notification and then post the data. How I can guarantee a strict sequential order using AFNetworking?
回答1:
By default, operations run concurrently, with no guarantee of order. The only way to ensure that actions play is to prevent more than one request operation from running at a given time, by setting the operationQueue.maximumConcurrentOperations property to 1 (or, if you're not using a manager, make sure to enqueue operations into an operation queue with the property set thusly).
来源：https://stackoverflow.com/questions/21585471/how-send-request-with-afnetworking-2-in-strict-sequential-order