Why is my delegation between two vc's not working? - iphone

Question

I have two view controllers. My first is my menu which contains my highscore and a button which performs a modal segue to my second view controller which is my game. Whenever my player loses the game if he beat his highscore I want it to update on the menu.
Right now, when my player loses the game, I create a UIAlertView with 2 buttons, the first is main menu and the second is restart. Here is my simplified code with my attempting to update my high score via delegation.
#protocol highScoreProtocol <NSObject>
-(void)updateHighScore:(int) score;
#end
#interface ViewController : UIViewController <UIAlertViewDelegate> //i have this delegate implemented because i have a uiialertview
#property (nonatomic) int score;
#property (nonatomic, weak) id <highScoreProtocol> delegateHighScore;
#implementation ViewController
#synthesize score=_score;
#synthesize delegateHighScore=_delegateHighScore;
-(void)lostGame{
[self.delegateHighScore updateHighScore:self.score]; //this is where i try to call the method that should update my high score if necessary but this doesn't actually work
UIAlertView *losingScreen=[[UIAlertView alloc]initWithTitle:#"Game Over" message:[NSString stringWithFormat:#"Your Score Is %d", self.score] delegate:self cancelButtonTitle:#"Main Menu" otherButtonTitles:#"Restart", nil]; //once the user loses the game i have an alert view show giving the option to either restart the game or go to the main menu where the high score is
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
if (buttonIndex==0) {
//here i'm segueing back to my main menu because he would have pressed the 'main menu' button [self performSegueWithIdentifier:#"MainMenu" sender:self];
} else if (buttonIndex==1){
//here i just reset my attributes and reset my level because he would have pressed the 'restart button'
}
}
#end
#interface MenuVC : UIViewController <highScoreProtocol>
#property (weak, nonatomic) IBOutlet UILabel *labelHighScore; //the labelhighscore is the highscore number
#end
#implementation MenuVC
- (void)viewDidLoad
{
[super viewDidLoad];
ViewController *vc=[[ViewController alloc]init];
vc.delegateHighScore=self;//here is set the delegate as myself which i think i'm supposed to do for some reason
}
-(void)updateHighScore:(int)score{
if (score>[self.labelHighScore.text integerValue]) {
self.labelHighScore.text=[NSString stringWithFormat:#"%d", score];
}
NSLog(#"does this method even run");
// this is the method that updates the highscore which I want to run
// but it doesn't, notice I even made an 'nslog' to see if the method
// even runs but I never ever even got a log out in the debugger,
// so this method never runs.
}
If I just need a little help, or if I'm doing everything completely wrong and going about this task the wrong way, please say.

Answer 1

This doesn't work because this:
ViewController *vc=[[ViewController alloc]init];
vc.delegateHighScore=self;
Instantiates a NEW viewcontroller, that has completely nothing to do with the one you are interacting with.
I assume you are using storyboards so, create an identifier for your viewcontroller (on the interface builder -> select your viewcontroller -> identity inspector tab -> write a name where it says Storyboard ID)
And then add this instead of the previous code:
ViewController *vc = [self.storyboard instantiateViewControllerWithIdentifier:#"yourIdentifier"];
vc.delegateHighScore = self;
Edit:
Add this to your button action (but delete the segue from the interface builder AND delete this code from the viewDidLoad)
ViewController *vc = [self.storyboard instantiateViewControllerWithIdentifier:#"yourIdentifier"];
vc.delegateHighScore = self;
[self presentModalViewController:vc animated:YES];

Answer 2

Since you create a local variable, vc, in your viewDidLoad method, this is not the same one that you create in the button method where you create your modal segue. That's not the right place to set the delegate. Set yourself to the delegate in that button method using whatever reference you create (or have) to the instance of ViewController that you're segueing to. If you need more information or a code sample, post that button method, so I can see how you are segueing.
After Edit: Then you should implement prepareForSegue:sender: and do this:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
[(ViewController *)[segue destinationViewController] setDelegate:self];
}