Question

我正在尝试在SKScene中创建一个UIRotationGestureRecognizer，并将其添加到场景视图中。当我将手势添加到视图时，我将其目标指定给场景，并将动作指定给场景中的方法。场景的方法永远不会被调用，手势识别器的视图属性始终为NULL。

//
//  MyScene.h
//  Rotate SpaceShip
//

//  Copyright (c) 2014 Andrew Paterson. All rights reserved.
//

#import <SpriteKit/SpriteKit.h>

@interface MyScene : SKScene <UIGestureRecognizerDelegate>

@end

实施：

//
//  MyScene.m
//  Rotate SpaceShip
//
//  Created by Andrew Paterson on 2/23/14.
//  Copyright (c) 2014 Andrew Paterson. All rights reserved.
//

#import "MyScene.h"
@interface MyScene ()
@property (strong, nonatomic)UIRotationGestureRecognizer *rotationGestureRecognizer;
@end
@implementation MyScene

-(id)initWithSize:(CGSize)size {    
    if (self = [super initWithSize:size]) {
        /* Setup your scene here */

        self.backgroundColor = [SKColor colorWithRed:0.15 green:0.15 blue:0.3 alpha:1.0];

        SKSpriteNode *spaceShip = [SKSpriteNode spriteNodeWithImageNamed:@"Spaceship"];
        spaceShip.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame));
        spaceShip.name = @"spaceship";

        [self addChild:spaceShip];

        self.rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc]
                                          initWithTarget:self
                                          action:@selector(handleRotation:)];
        self.rotationGestureRecognizer.delegate = self;
        [self.view addGestureRecognizer:self.rotationGestureRecognizer];
    }
    return self;
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    /* Called when a touch begins */
    [super touchesBegan:touches withEvent:event];

}

-(void)update:(CFTimeInterval)currentTime {
    /* Called before each frame is rendered */
}
- (void)moveFromScene{
    [self.view removeGestureRecognizer:self.rotationGestureRecognizer];
}
- (void)handleRotation:(UIRotationGestureRecognizer *)recognizer{
    SKSpriteNode *spaceship = (SKSpriteNode *)[self childNodeWithName:@"spaceship"];
    if (!(recognizer.state == UIGestureRecognizerStateEnded)){

    spaceship.zRotation =  (spaceship.zRotation + (recognizer.rotation - spaceship.zRotation));

    }

}
@end

当我在更新时中断并打印手势识别器

时，调试器输出此信息

(lldb) po self.rotationGestureRecognizer.view
 nil
(lldb) po self.rotationGestureRecognizer
<UIRotationGestureRecognizer: 0xa04d570; state = Possible; view = <(null) 0x0>; target= <(action=handleRotation:, target=<MyScene 0x9632380>)>>
(lldb)

非常感谢任何帮助解决这个非常奇怪的问题。

Answer 1

显然，在initWithSize中添加手势识别器时，sprite工具包中存在一个导致此问题的错误：如果将其移动到didMoveToView：问题就会消失。

UIRotationGestureRecognizer无法在SKScene中调用处理程序方法

1 个答案: