Question

I have a scoreboard app that has many UITextFields that holds the scores for each player of every round. When clicking on the text field, instead of just using the keyboard to input a score, I want to create another viewController (a popover or a page-curl modal segue would work). This 2nd view controller has a special calculator the player can use to input their score. So basically every score box triggers an action to the calculator view. Once I have the result on the calculator view, I want to dismiss the view and have the score that was just calculated to appear in the score box that cause the segue to occur. (I want to transfer the a specific UILabel.text from the 2nd view Controller back to the first view controller).

After trying a bunch ways to do this, I feel like I must learn about delegates. I’m trying to wrap my head around this concept and see if this really does apply to what I’m trying to do. It seems I have to somehow have my UITextFields (the score boxes) “listen” or “wait for” the calculator result to change. Is this correct? Am I over complicating things? Do I need to learn about delegates to make this work?

Answer 1

Yes you can play around with delegation , that way you can achieve what you want to.Also you can use “NSNotificationCenter” to listen to specific events and call methods or whatever you want to.

Like this:

Add an observer :

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

then post it from where you want to like you said from textfield input:

[[NSNotificationCenter defaultCenter] 
        postNotificationName:@"TestNotification" 
        object:self];

And receive it in a method like this

-(void) receiveTestNotification:(NSNotification *) notification
{
    // [notification name] should always be @"TestNotification"
    // unless you use this method for observation of other notifications
    // as well.

    if ([[notification name] isEqualToString:@"TestNotification"])
        NSLog (@"Successfully received the test notification!");
}