Game won't send high score to Game Center

Question

I have managed to get my game to sign the player into game center on launch however when a highscore is reached it just saves it on the game rather than sending it to game centre. Wherever i put the

[self reportScore];

it seem to make the simulator crash, I have attached my view controller.m file if you could help me with a method to make my game send the highscore to Game Center so i can move on to posting the leaderboard on to displaying the leaderboard in the app. I am following this tutorial by the way http://www.appcoda.com/ios-game-kit-framework/

 #import "ViewController.h"
 #import <GameKit/GameKit.h>
 #import <UIKit/UIKit.h>
 #import <iAd/iAd.h>

 @interface ViewController ()

 @property (nonatomic, strong) NSString *leaderboardIdentifier;
 @property (nonatomic,assign) BOOL gameCenterEnabled;

 -(void)authenticateLocalPlayer;
 -(void)reportScore;

 @end

 @implementation ViewController

-(void)reportScore{
     GKScore *score = [[GKScore alloc]   initWithLeaderboardIdentifier:_leaderboardIdentifier];
     score.value = HighScoreNumber;

     [GKScore reportScores:@[score] withCompletionHandler:^(NSError  *error) {
         if (error != nil) {
             NSLog(@"%@", [error localizedDescription]);
         }
     }];
}

-(void)authenticateLocalPlayer;{
     GKLocalPlayer *localPlayer = [GKLocalPlayer localPlayer];

     localPlayer.authenticateHandler = ^(UIViewController  *viewController, NSError *error){
         if (viewController != nil) {
             [self presentViewController:viewController animated:YES  completion:nil];
         } else {
             if ([GKLocalPlayer localPlayer].authenticated) {
                 _gameCenterEnabled = YES;

                // Get the default leaderboard identifier.
                [[GKLocalPlayer localPlayer]  loadDefaultLeaderboardIdentifierWithCompletionHandler:^(NSString         *leaderboardIdentifier, NSError *error) {
                    if (error != nil) {
                        NSLog(@"%@", [error localizedDescription]);
                    } else {
                        _leaderboardIdentifier = leaderboardIdentifier;
                    }
                }];
            } else {
                _gameCenterEnabled = NO;
            }
        }
    };
}

- (void)viewDidLoad
{
    [self authenticateLocalPlayer];

     HighScoreNumber = [[NSUserDefaults standardUserDefaults]  integerForKey:@"HighScoreSaved"];
     HighScore.text = [NSString stringWithFormat:@"High Score: %li", (long)HighScoreNumber];

     [super viewDidLoad];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

#pragma mark iAd Delegate Methods

-(void)bannerViewDidLoadAd:(ADBannerView *)banner {
    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:1];

    [banner setAlpha:1];

    [UIView commitAnimations];
}

-(void)bannerView:(ADBannerView *)banner didFailToReceiveAdWithError:(NSError *)error {
    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:1];

    [banner setAlpha:0];

    [UIView commitAnimations];
}

@end

Answer 1

Can you try whether this simple snippet works for you? _localPlayer refers to an instance variable which is set with the authentication handler.

- (IBAction)doAddAScore:(id)sender {
    GKLocalPlayer *lp = [GKLocalPlayer localPlayer];
    NSInteger score = 100;
    if (lp && lp.isAuthenticated) {
        NSString *lbid = @"your.leaderboard.id";
        GKScore *gkScore = [[GKScore alloc] initWithLeaderboardIdentifier:lbid player:lp];
        gkScore.value = score;
        [GKScore reportScores:@[gkScore] withCompletionHandler:^(NSError * _Nullable error) {
            NSLog(@"GKScore::reportScores completed - error : %@", error);
        }];
    } else {
        NSLog(@"reporting score: localPlayer nil or not authenticated");
    }
}

This code is from a test prototype of mine which I use for resolving game invites and the score submission just worked. There is no other part of the code which deals with score submission.