网络丢失，屏幕锁定解锁

Question

Encountered a very weird problem, using simple AFNetworking downloading operation, even tried with simple NSURLConnection operation, connection fails if you keep your app running, and lock screen and then unlock. Works absolutely fine in background though.

Any one encountered similar problem with NSURLConnection want to share some solution?

Thanks.

Answer 1

It looks like an iOS bug. Weird, but lock screen action affects NSURLSession somehow, so that it stops working and returns NSURLErrorNetworkConnectionLost . So in my app I gave up using shared session. I either use a new session object for every request or (if I need to maintain one session constantly) recreate it every time the screen gets unlocked. And it works. For users of AFNetworking or any other third party library working on top of NSURLSession the situation is harder, of course. You'll need to correct the code of the library, which is definitely not a good thing, but I think there's no other choice

Answer 2

Very helpful Andrey Chernukha , In my case, figured out that you don't necessary need to recreate new session every time. I ended up using array to save running NSURLSessionDataTasks and after phone is unlocked resume them.

Steps:

1. I created array NSMutableArray *dataTasksToResume

2. In - (void)applicationWillResignActive:(UIApplication *)application I saved all tasks to dataTasksToResume array

3. Cancel all running NSURLSessionDataTasks
4. In - (void)applicationDidBecomeActive:(UIApplication *)application get all tasks from array and resuming them (re-creating them)
5. Enjoy!

Hope it helps.