Integrate Gamecenter in cocos2d game

Then follow these instructions:

//0.0 Add GameKit Framework to Project (Ask If you don't know how to do this ;) )

//0. Change "[window addSubview: viewController.view];" in the AppDelegate.m to: //Do this if you're using any release of cocos2D after 0.99.5:

window.rootViewController = viewController;

//1. Add Gamekithelper.h / .m to project

//2. Include following delegate in given header:

<GameKitHelperProtocol>

//3. Add Delegate Methods to .m

//4. Add GameKitHelper to "Scene":

GameKitHelper *gkHelper = [GameKitHelper sharedGameKitHelper];
gkHelper.delegate = self;
[gkHelper authenticateLocalPlayer];

//Adding score to leaderboard:

GameKitHelper *gkHelper = [GameKitHelper sharedGameKitHelper];
[gkHelper submitScore:scoreValue category:@"LeaderboardID"];

//Adding achievement completion:

GameKitHelper *gkHelper = [GameKitHelper sharedGameKitHelper];
[gkHelper reportAchievementWithID:@"AchievementID" percentComplete:100];

These are the delegate Methods that need to be added mentioned in Step #3:

#pragma mark GameKitHelper delegate methods
-(void) onLocalPlayerAuthenticationChanged
{
    GKLocalPlayer* localPlayer = [GKLocalPlayer localPlayer];
    CCLOG(@"LocalPlayer isAuthenticated changed to: %@", localPlayer.authenticated ? @"YES" : @"NO");

    if (localPlayer.authenticated)
    {
        GameKitHelper* gkHelper = [GameKitHelper sharedGameKitHelper];
        [gkHelper getLocalPlayerFriends];
        //[gkHelper resetAchievements];
    }   
}
-(void) onFriendListReceived:(NSArray*)friends
{
    CCLOG(@"onFriendListReceived: %@", [friends description]);
    GameKitHelper* gkHelper = [GameKitHelper sharedGameKitHelper];
    [gkHelper getPlayerInfo:friends];
}
-(void) onPlayerInfoReceived:(NSArray*)players
{
    CCLOG(@"onPlayerInfoReceived: %@", [players description]);


}
-(void) onScoresSubmitted:(bool)success
{
    CCLOG(@"onScoresSubmitted: %@", success ? @"YES" : @"NO");
}
-(void) onScoresReceived:(NSArray*)scores
{
    CCLOG(@"onScoresReceived: %@", [scores description]);
    GameKitHelper* gkHelper = [GameKitHelper sharedGameKitHelper];
    [gkHelper showAchievements];
}
-(void) onAchievementReported:(GKAchievement*)achievement
{
    CCLOG(@"onAchievementReported: %@", achievement);
}
-(void) onAchievementsLoaded:(NSDictionary*)achievements
{
    CCLOG(@"onLocalPlayerAchievementsLoaded: %@", [achievements description]);
}
-(void) onResetAchievements:(bool)success
{
    CCLOG(@"onResetAchievements: %@", success ? @"YES" : @"NO");
}
-(void) onLeaderboardViewDismissed
{
    CCLOG(@"onLeaderboardViewDismissed");

    GameKitHelper* gkHelper = [GameKitHelper sharedGameKitHelper];
    [gkHelper retrieveTopTenAllTimeGlobalScores];
}
-(void) onAchievementsViewDismissed
{
    CCLOG(@"onAchievementsViewDismissed");
}
-(void) onReceivedMatchmakingActivity:(NSInteger)activity
{
    CCLOG(@"receivedMatchmakingActivity: %i", activity);
}
-(void) onMatchFound:(GKMatch*)match
{
    CCLOG(@"onMatchFound: %@", match);
}
-(void) onPlayersAddedToMatch:(bool)success
{
    CCLOG(@"onPlayersAddedToMatch: %@", success ? @"YES" : @"NO");
}
-(void) onMatchmakingViewDismissed
{
    CCLOG(@"onMatchmakingViewDismissed");
}
-(void) onMatchmakingViewError
{
    CCLOG(@"onMatchmakingViewError");
}
-(void) onPlayerConnected:(NSString*)playerID
{
    CCLOG(@"onPlayerConnected: %@", playerID);
}
-(void) onPlayerDisconnected:(NSString*)playerID
{
    CCLOG(@"onPlayerDisconnected: %@", playerID);
}
-(void) onStartMatch
{
    CCLOG(@"onStartMatch");
}
-(void) onReceivedData:(NSData*)data fromPlayer:(NSString*)playerID
{
    CCLOG(@"onReceivedData: %@ fromPlayer: %@", data, playerID);
}

 出处：http://stackoverflow.com/questions/6278085/integrate-gamecenter-in-cocos2d-game/6290129