Bird，GameWorld和GameScene是我项目中的三个自定义类。
我在Gameworld类中有一个类型为Bird（作为属性）的对象。我在GameScene类中具有Bird和Gameworld类型的对象。现在在Gamecene课上，当我这样做时：
_bird = [_gameWorld bird];
错误提示：
非目标C指针类型'int *'的隐式转换为'Bird'
*'不适用于ARC
为什么会这样呢？
编辑：
GameScene.h
#import <SpriteKit/SpriteKit.h>
#import "Bird.h"
#import "ScrollHandler.h"
#import "Pipe.h"
#import "GameWorld.h"
@interface GameScene : SKScene <SKPhysicsContactDelegate>{
int _midPointY;
float _gameHeight;
NSString *_gameName;
NSString *_getReady;
Bird *_myBird;
NSTimeInterval _dt;
float bottomScrollerHeight;
GameWorld *_myWorld;
}
@property (nonatomic) SKSpriteNode* backgroundImageNode;
@property (nonatomic) SKSpriteNode* greenBird;
@property (nonatomic) NSTimeInterval lastSpawnTimeInterval;
@property (nonatomic) NSTimeInterval lastUpdateTimeInterval;
@end
GameWorld.h
#import <Foundation/Foundation.h>
#import <SpriteKit/SpriteKit.h>
#import "Bird.h"
#import "ScrollHandler.h"
typedef NS_ENUM(NSInteger, GameState){
MENU,
READY,
RUNNING,
GAMEOVER,
HIGHSCORE
};
@interface GameWorld : NSObject <ScrollHandlerDelegate>{
float _runTime;
GameState _currentState;
}
@property (nonatomic, strong) ScrollHandler *scroller;
@property (nonatomic, strong) Bird *bird;
@property (nonatomic, assign) int midPointY;
@property (nonatomic, assign) int score;
@property (nonatomic, strong) SKSpriteNode *bg;
@property (nonatomic, strong) NSArray *birds;
@property (nonatomic, strong) SKSpriteNode *birdNode;
@end
GameScene.m
#import "GameScene.h"
#define UPWARD_PILLER @"Upward_Green_Pipe"
#define Downward_PILLER @"Downward_Green_Pipe"
static const uint32_t pillerCategory = 0x1 << 0;
static const uint32_t birdCategory = 0x1 << 1;
static const uint32_t grassCategory = 0x1 << 2;
static const float BG_VELOCITY = (TIME * 60);
static inline CGPoint CGPointAdd(const CGPoint a, const CGPoint b)
{
return CGPointMake(a.x + b.x, a.y + b.y);
}
static inline CGPoint CGPointMultiplyScalar(const CGPoint a, const CGFloat b)
{
return CGPointMake(a.x * b, a.y * b);
}
@implementation GameScene
-(id)initWithSize:(CGSize)size
{
if (self = [super initWithSize:size])
{
self.anchorPoint = CGPointMake(0, 1);
self.yScale = -1;
//To detect collision detection
self.physicsWorld.contactDelegate = self;
_myWorld = [[GameWorld alloc] initWithMidPointY:_midPointY];
[self initGameObjects];
[self initAssets];
[self setCoinAnimation];
}
return self;
}
-(void) initGameObjects {
_myBird = [_myWorld bird]; //here is the problem
}
-(void) initAssets {
//initialize other assets
}
-(void) setCoinAnimation {
//initialize other assets
}
@end
鸟
#import "GameWorld.h"
@import UIKit;
@interface Bird : NSObject {
CGPoint _position;
CGPoint _velocity;
CGPoint _acceleration;
float _rotation;
float _originalY;
int _width;
int _height;
int _dieCount;
bool _isAlive;
}
@end
注意：我刚刚发现删除导入的“ Gameworld.h”
从“ Bird.h”中消失，该错误消失并且正在运行。导入是在那里意外完成的，因此不需要。但是我不为什么会导致错误。
最佳答案
就像您在最后提到的那样，那是唯一的问题。
那到底是怎么回事？
当您将Gameworld导入到Bird接口文件中时，您的Gameworld本身就有一个名为bird的变量，其类型为Bird。然后，您继续并在随后的几行中定义了Bird类。在此之前，编译器不会知道Bird对象是什么，并且默认情况下将其假定为int。
如果您要如何在Gameworld类中声明Bird对象，则无需使用接口将其导入，而只需使用前向声明即可。
@class Gameworld;
这告诉编译器确实存在一个名称为
Gameworld的类。关于ios - ARC不允许将非客观C指针类型'int *'隐式转换为'Bird *'，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/29465707/