的Cocos2D：無法調用父類

Question

在我的場景我有

//.h

#import "cocos2d.h" 

#import "FixedBackground.h" 
@class FixedBackground; 

#import "JoinedMapsLayer.h" 
@class JoinedMapsLayer; 


@interface JoinedMapsScene : CCScene { 


    FixedBackground *fixedBackground; 
    JoinedMapsLayer *joinedMapsLayer; 

} 

@property(nonatomic, retain) FixedBackground *fixedBackground; 
@property(nonatomic, retain) CCNode *joinedMapsLayer; 

+(id) scene; 

- (void) moveBG:(float)x andY:(float)y; 
- (int) getInt; 


@end 

//.m

#import "JoinedMapsScene.h" 

@implementation JoinedMapsScene 

@synthesize fixedBackground; 
@synthesize joinedMapsLayer; 

+(id) scene { 

    // 'scene' is an autorelease object. 
    CCScene *scene = [CCScene node]; 

    // 'layers' are an autorelease object. 
    JoinedMapsScene *layer1 = [JoinedMapsScene node]; 

    // add layers as a childs to scene 
    [scene addChild: layer1]; 

    return scene; 
} 

-(id) init { 

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

     fixedBackground = [FixedBackground node]; 
     joinedMapsLayer = [JoinedMapsLayer node]; 

     // add layers as a children of the scene 
     [self addChild:fixedBackground]; 
     [self addChild:joinedMapsLayer]; 

    } 
    return self; 
} 

- (int)getInt { 
    return 100; 
} 

- (void) dealloc{ 

    [super dealloc]; 
} 

@end 

在joinedMapsLayer init方法我嘗試調用getInt並返回它的值爲100，但它返回0：

NSLog（@「％d」，[（JoinedMapsScene *）self.parent getInt]）;

任何線索爲什麼發生這種情況？我的場景寫錯了嗎？

Answer 1

當您撥打[JoinedMapsLayer node]時，您還沒有添加joinedMapsLayer作爲JoinedMapsScene實例的子項，所以它沒有父項。