Wrong class type in objective C
- by Max Hui
I have a parent class and a child class. GameObjectBase (parent) GameObjectPlayer(child). When I override a method in Child class and call it using
[myPlayerClass showNextFrame]
It is calling the parent class one. It turns out in the debugger, I see the myPlayerClass was indeed class type GameObjectBase (which is the parent class) How come?
GameObjectBase.h
#import <Foundation/Foundation.h>
#import "cocos2d.h"
@class GameLayer;
@interface GameObjectBase : NSObject
{
/* CCSprite *gameObjectSprite; // Sprite representing this game object
GameLayer *parentGameLayer; */ // Reference of the game layer this object
// belongs to
}
@property (nonatomic, assign) CCSprite *gameObjectSprite;
@property (nonatomic, assign) GameLayer *parentGameLayer;
// Class method. Autorelease
+ (id) initWithGameLayer:(GameLayer *) gamelayer
imageFileName:(NSString *) fileName;
// "Virtual methods" that the derived class should implement.
// If not implemented, this method will be called and Assert game
- (void) update: (ccTime) dt;
- (void) showNextFrame;
@end
GameObjectPlayer.h
#import <Foundation/Foundation.h>
#import "GameObjectBase.h"
@interface GameObjectPlayer : GameObjectBase
{
int direction;
}
@property (nonatomic) int direction;
@end
GameLayer.h
#import "cocos2d.h"
#import "GameObjectPlayer.h"
@interface GameLayer : CCLayer
{
}
// returns a CCScene that contains the GameLayer as the only child
+(CCScene *) scene;
@property (nonatomic, strong) GameObjectPlayer *player;
@end
When I call examine in debugger what type "temp" is in this function inside GameLayer class, it's giving parent class GameObjectBase instead of subclass GameObjectPlayer
- (void) update:(ccTime) dt
{
GameObjectPlayer *temp = _player;
[temp showNextFrame];
}
