Question

I get this exception when i try to create a new layer. So , basically i have a standart cocos2d template , i just removed HelloWorldLayer class and created a new class called GameScene, were i defined +scene method , init and dealloc methods

GameScene.h

#import "cocos2d.h"

@interface GameScene : CCLayer {}

+(id) scene;

@end

GameScene.m

#import "GameScene.h"

@implementation GameScene 

    +(id) scene {

        CCScene *scene = [CCScene node];
        GameScene *layer = [GameScene node];

        [scene addChild:layer];
        return self;
    }

    -(id) init {

        if ((self = [super init])) {

            CCLOG(@"New GameScene");
        }

        return self;
    }

    -(void) dealloc {

        [super dealloc];
    }

    @end

I my appDelegate , instead of old layer , create new one from GameScene

- (void) applicationDidFinishLaunching:(UIApplication*)application
{
    …

    // Run the intro Scene
    [[CCDirector sharedDirector] runWithScene: [GameScene scene]];
}

Console output shows :

2012-02-06 20:37:04.284 Doodle[3908:10a03] +[GameScene onEnter]: unrecognized selector sent to class 0x1098c4
2012-02-06 20:37:04.288 Doodle[3908:10a03] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+[GameScene onEnter]: unrecognized selector sent to class 0x1098c4'

Answer 1

I figure it out. Instead of returning an id type for method +scene , it should be a CCScene value.

// in header also modify type of returned value


    +(CCScene *) scene {

            CCScene *scene = [CCScene node];
            GameScene *layer = [GameScene node];

            [scene addChild:layer];
            return self;
        }

I’m still confused of why id is not working cause it can be every type , even CCScene type.