Question

我的联系人侦听器代码中出现EXC_BAD_ACCESS错误。以下是代码：

主对象类（GameObjects），所有对象都通过它们进行子类化：

GameObjects.h：

#import "cocos2d.h"
#import "CCNode.h"
#import "CCPhysicsSprite.h"
#import "Box2D.h"
#include <math.h>

@interface GameObjects : CCNode {
    //b2Body* objectBody_;
}

-(b2Body*)getObjectBody;
-(void)objectsTouched:(GameObjects*)otherObject;
@end

GameObjects.mm（现在我只想让CCLOG判断它是否正常工作）：

#import "GameObjects.h"

@implementation GameObjects

-(b2Body*)getObjectBody    {
}

-(void)objectsTouched:(GameObjects*)otherObject   {
   CCLOG(@"it's working");
}

@end

ContactListenerTest.h：

#import <Foundation/Foundation.h>
#import "cocos2d.h"
#import "Box2D.h"
#import "Enemy.h"
#import "Sprite.h"
#import "GameObjects.h"



class ContactListenerTest : public b2ContactListener    {
public:

   b2World* world;
   void BeginContact(b2Contact* contact);
};

ContactListenerTest.mm：

#import "ContactListenerTest.h"

void ContactListenerTest:: BeginContact(b2Contact *contact)
{

    b2Fixture       *fixtureA = contact->GetFixtureA();
    b2Fixture       *fixtureB = contact->GetFixtureB();
    b2Body          *fixtureABody = fixtureA->GetBody();
    b2Body          *fixtureBBody = fixtureB->GetBody();

    GameObjects* spriteObject = (GameObjects*)fixtureABody->GetUserData();
    GameObjects* spriteObject2 = (GameObjects*)fixtureBBody->GetUserData();

    [spriteObject objectsTouched:spriteObject2];
    [spriteObject2 objectsTouched:spriteObject];

}

当我收到EXC_BAD_ACCESS错误时，控制台中会打印以下内容：

-[Enemy objectsTouched:]: unrecognized selector sent to instance 0x8558840

Enemy是GameObjects的子类之一。

Answer 1

验证userdata对象实际上是GameObjects类：

NSAssert1([spriteObject isKindOfClass:[GameObjects class]], 
          @"userdata %@ not a game object", spriteObject);
NSAssert1([spriteObject2 isKindOfClass:[GameObjects class]], 
          @"userdata 2 %@ not a game object", spriteObject2);

Answer 2

初始化GameObject时，应确保创建的主体的UserData指向GameObject。像这样：

objectBody_->SetUserData(self);

联系人侦听器的EXC_BAD_ACCESS问题

2 个答案: