CODEWITHSUNDEEP
iosobjective-ciphonefilesave
Nir
Nir

Reputation: 25

Save data from textField into a file when the application has closed or terminated

In my application has a view controller named "Home" with a textField. I read about applicationDidEnterBackground and applicationWillTerminate methods in the AppDelegate file. I know how to create, save, read data from a file.

My question is, How I can get an NSString from the "Home" viewController (that there store the textField data) to the AppDelegate applicationDidEnterBackground method and do there all my things with that data?

Upvotes: 0

Views: 127

Answers (2)

Tanuj
Tanuj

Reputation: 531

You can do this with the help of this inside your controller:

-(id)init
{
    if((self = [super init]))
    {
        [[NSNotificationCenter defaultCenter]   addObserver:self
                                                   selector:@selector(appDidEnterBackground:)
                                                       name:UIApplicationDidEnterBackgroundNotification
                                                     object:[UIApplication sharedApplication]];
    }
    return self;
}

-(void)appDidEnterBackground:(NSNotification *)note {
    NSLog(@"appDidEnterBackground");
}

you can also use applicationWillTerminate in place of UIApplicationDidEnterBackgroundNotification

Upvotes: 0

gregyoung14
gregyoung14

Reputation: 347

You could use NSNotificationCenter to register for a notification in your view controller that fires off whenever you enter applicationDidEnterBackground or applicationWillTerminate.

So in either of those methods you put something like

[[NSNotificationCenter defaultCenter] postNotificationName:@"someDescriptiveName" object:self userInfo:@{@"key" : @"value"}];

userInfo expects an NSDicitonary and you can pass it any type of object in there, in your case you dont need to pass anything from here back to your viewcontroller, your just using it as a means to let your view controller know the app is closing.

In your view controller you would register for that notification with something like this

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(methodToCall:) name:@"someDescriptiveName" object:nil];

Then whenever your appDelegate post that notification, your view controller which is registered to listen for it would fire off "methodToCall" which can be a method you right to do anything and it takes in an nsnotification which then lets you access the nsdicitonary its carrying. 

- (void)methodToCall:(NSNotification *)notif{
NSLog(@"methodToCall fired with data %@",[[notif userInfo]valueForKey:@"key"]);}

Upvotes: 1

Related Questions