Knowing the app. launc in Objective C - ios

Question

The app. delegate has the method that gets invoked when the app launches. Pain is my app is not following MVC and I have to reset many text fields to empty when the app. launches(not concerned about first launch). These txt fields are not created in app delegate so i cannot set them in app delegate (as the txt fields are not accessible). how can i know the app has launched in the new class to reset the fields . Is there any condition like
if(application.HasAppLaunced)
{
}
KIndly help

Answer 1

You could register your view controller as an observer of event
UIApplicationDidEnterBackgroundNotification
or
UIApplicationWillEnterForegroundNotification
in your view controller somewhere in viewDidLoad:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(appEnteredBackground)
name:UIApplicationDidEnterBackgroundNotification
object:nil];
and add this method to reset your fields, you can reset all fields here:
- (void)appEnteredBackground{
[textField setText:#""];
}
don't forget to unregister your view controller, put this in some appropriate location:
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIApplicationDidEnterBackgroundNotification object:nil];

Answer 2

I don't completely understand what are you asking for, but if the question is how to detect whather app is active you may use following condition:
[[UIAppication sharedApplication] applicationState] == UIAppicationStateActive

Answer 3

Try This
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Reset your text fields here
}

Answer 4

Try this one.. You can call a method to empty thetextfields using NSNotificationCenter
You can write the following line in AppDelegate.
[[NSNotificationCenter defaultCenter]postNotificationName:#"EmptyFields" object:nil];
You can write the following line in viewDidLoad method.
[[NSNotificationCenter defaultCenter]addObserver:self selector:#selector(setEmpty) name:#"EmptyFields" object:nil];
You can do textfields empty in the following method. You can write it in your ViewController.
- (void) setEmpty{
NSLog(#"Empty....");
}