Question

I need to change a data (a label) from the app’s delegate method ApplicationDidEnterForeground without allocating a new view. The view is called “Reminder”, so I imported it into the delegate and I can access its data only if I allocate it (Reminder *anything = [Reminder alloc…etc), but since I want to change the current view loaded I need to have direct access to the view that’s already loaded.

How would I do to change the main view’s label from the delegate as soon as my application enters foreground?

obs: I know I can do it on -(void)ViewDidLoad or -(void)ViewWillAppear but it won’t solve my problem, since it won’t change the label if, for example, the user opens the app through a notification box (slide icon when phone is locked). In that case, none of the above methods are called if the app was open in background.

I don’t know if I was clear, hope I was. Thank you in advance.

Answer 1

IF you are using storyboards, you can do this to access the current view being seen

- (void)applicationDidEnterBackground:(UIApplication *)application
{ 
UINavigationController *a=_window.rootViewController;
Reminder *rem = a.topViewController;
rem.label.text=@"test";
}

IF not using story boards

When I create views that I need to access later, I define them as a property, like this

on AppDelegate.h

//@interface SIMCAppDelegate : UIResponder <..........>
//{
//Some variables here
//}

//Properties here
@property (strong, nonatomic) Reminder *reminder;

//Some method declaration here
//eg: -(void) showSomething;

on AppDelegate.m

//@implementation AppDelegate

@synthesize reminder;

so when I alloc/init the view like this

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
//codes before here

self.reminder = [[Reminder alloc] init];
self.reminder.label.text = @"OLD LABEL";
//codes after here
}

I will be able to access it again after allocation on other methods, like this

- (void)applicationWillEnterForeground:(UIApplication *)application
{

self.reminder.label.text = @"NEW LABEL";
}