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下面是根据颜色和其他一些属性来处理创建球的方法。createBall 方法返回一个 CCPhysicsSprite。numberOfBallsToCreate 返回每种颜色中的一种，但黑色返回五种。

-(void)ballCreation:(b2World*)world inLayer:(CCLayer*)layer   {

CGSize s = [[CCDirector sharedDirector] winSize];
ballType = blackBall;

for (int i = 0; i < [self numberOfBallsToCreate]; i++) {


switch (ballType) {
    case greenBall: 
        [self createBall:world inLayer:layer atPosition:[self ballPosition] ballImage:@"greenBall.png"];

        break;

    case redBall: 
        [self createBall:world inLayer:layer atPosition:[self ballPosition] ballImage:@"redBall.png"];

        break;

    case blueBall:  
        [self createBall:world inLayer:layer atPosition:[self ballPosition] ballImage:@"blueBall.png"];

        break;

    case blackBall:   
        [blackBallArray addObject:[self createBall:world inLayer:layer atPosition:[self ballBirdPositions] ballImage:@"blackBall.png"] ];

      break;

    default:
        break;
}
}

}

下面还有一种方法，我每 1/60 秒更新一次，对每个球施加力。除黑球外，所有球的更新都运行良好。

-(void)updateBalls   {

switch ([self getBallType]) {
    case greenBall:
        [self applyGreenForce];
        break;

    case redBall:
        [self applyRedForce];
        break;

    case blueBall:
        [self applyBlueForce];
        break;

    case blackBall:    {
        //[self applyBlackForce];
        createdBlackBallArray = [self getBlackBallArray];
        CCLOG(@"the createdBlackBallArray count is %d", createdBlackBallArray.count); // always prints zero
        if (createdBlackBallArray != NULL) {
            //CCLOG(@"code reached here");
            for (int i = 0; i < createdBlackBallArray.count; i++) {
                CCPhysicsSprite* blackBallPhysicsSprite = [createdBlackBallArray objectAtIndex:i];
                //if (blackBallPhysicsSprite.b2Body != NULL) {
                b2Vec2 ballForce = b2Vec2(1.0, 0.5);
                blackBallPhysicsSprite.b2Body->ApplyForce(ballForce, blackBallPhysicsSprite.b2Body->GetWorldCenter() );

            }

            }
        }

        break;

    default:
        break;
}

上面的 CCLOG 始终为数组计数提供零，因此不会施加力。我不确定我做错了什么。getBlackBallArray 详细信息如下：

-(NSMutableArray*)getblackBallArray   {

return blackBallArray;
}

我该如何解决这个问题？

更新

这是初始化数组的 initWithBall 方法。

-(id)initWithBall:(b2World*)world inLayer:(CCLayer*)layer {

[self ballCreation:world inLayer:layer];

blackBallArray = [[NSMutableArray alloc] init];
createdBlackBallArray = [[NSMutableArray alloc] init];
return self;
}

Ball.h 类的一部分如下：

#import "GameObjects.h"

typedef NS_ENUM(NSUInteger, ballTypes) {
blueBall = 0, 
blackBall = 1, 
redBall = 2,  
greenBall = 3,  


};

@interface Ball : CCNode    {

b2Body* ballBody;
b2World* ballWorld;
CCLayer* ballLayer;
ballTypes ballType;
NSString* ballImageName;
NSMutableArray* blackBallArray;
NSMutableArray* createdBlackBallArray;

}

-(void)updateBalls;
@end
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1 回答 1

4

您在代码中犯了一个小错误。在调用 ballCreation 方法后，您已经初始化了 blackBallArray。

它应该是这样的：

-(id)initWithBall:(b2World*)world inLayer:(CCLayer*)layer {
if ((self = [super init]) != nil)
{

//Initialize array first
  blackBallArray = [[NSMutableArray alloc] init];
  createdBlackBallArray = [[NSMutableArray alloc] init];

  [self ballCreation:world inLayer:layer];
}
  return self;
}

一个警告。发布帖子时，请始终确保仅添加最重要的代码。你真的提出了很多代码，这使得它有点令人困惑。快乐编码。

于 2013-06-24T07:18:12.287 回答