CODEWITHSUNDEEP
iphonecocoa-touch
sidhu
sidhu

Reputation: 181

beginBackgroundTaskWithExpirationHandler

I am making an application where audio will play in the background. In the following code, bgTask is undeclared. What kind of object should bgTask be?

- (void)applicationDidEnterBackground:(UIApplication *)application 
{
    UIApplication  *app = [UIApplication sharedApplication];
    bgTask = [app beginBackgroundTaskWithExpirationHandler:^{ 
        [app endBackgroundTask:bgTask]; 
        bgTask = UIBackgroundTaskInvalid;
    }];

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{});

    [app endBackgroundTask:bgTask]; 
    bgTask = UIBackgroundTaskInvalid;
}

Upvotes: 14

Views: 23730

Answers (3)

Dilip Manek
Dilip Manek

Reputation: 9143

You are using the bgTask in the block so you have to declare it like this..

__block UIBackgroundTaskIdentifier bgTask = 0;

__block will allow this variable to use in the block method. And its have double underscore.

Upvotes: 2

willcodejavaforfood
willcodejavaforfood

Reputation: 44063

You need to declare bgTask before you assign:

UIBackgroundTaskIdentifier bgTask = 0;

Upvotes: 17

Bontarest
Bontarest

Reputation: 171

I cannot comment on previous answers, however to initialize UIBackgroundTaskIdentifier you should not set it to nil or 0. You should set it to:

UIBackgroundTaskInvalid

In the documentation UIBackgroundTaskInvalid says it should be used to initialize variables or to check for errors.

Upvotes: 10

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