CODEWITHSUNDEEP
iphoneobjective-ciosios4ios5
Whoami
Whoami

Reputation: 14408

how to invoke a function while the application goes into suspend mode in iOS?

I m new to the iOS. When i press home button in iPhone, application goes into suspend mode is what i know, in the program, how can i capture this event, and clear my local datas? Kindly advice.

Upvotes: 0

Views: 984

Answers (4)

Conrad Shultz
Conrad Shultz

Reputation: 8808

While you can implement the UIApplicationDelegate methods discussed by others, it is often more convenient (and arguably cleaner) to have objects that need to do clean up register themselves for the corresponding notifications:

UIApplicationDidEnterBackgroundNotification
UIApplicationWillResignActiveNotification

E.g.

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(myCleanupMethod:)
                                             name:UIApplicationDidEnterBackgroundNotification
                                           object:nil];

(If you go this route, don't forget to remove the observer when the observing object is deallocated.)

Upvotes: 0

Joel
Joel

Reputation: 16124

Use app delegate applicationWillResignActive method and UIBackgroundTaskIdentifier if needed. For example:

- (void)applicationWillResignActive:(UIApplication *)application {
    UIBackgroundTaskIdentifier backgroundTaskIdentifier = [application beginBackgroundTaskWithExpirationHandler:^(void) {
        [application endBackgroundTask:backgroundTaskIdentifier];
        //your cleanup code
    }];
}

Upvotes: 0

Michael Frederick
Michael Frederick

Reputation: 16714

You can use the following method from within your app delegate:

- (void)applicationWillResignActive:(UIApplication *)application

Apple explains when this delegate method is called:

Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.

Upvotes: 2

AJak
AJak

Reputation: 3873

Inside your delegate, put the code you want to call inside of these. One fires every time you background the application and the other fires when you come back.

- (void)applicationDidEnterBackground:(UIApplication *)application

- (void)applicationDidBecomeActive:(UIApplication *)application

Upvotes: 1

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