iOS 模拟器在随机时间段后停止正确识别手势

Question

抱歉，这个时间太长了。这对我来说是一个谜，正在寻找任何人可能有的指示。

iOS 模拟器中 UIGestureRecognizers 的工作方式和传递触摸点的方式似乎存在一个错误，该错误在模拟器重新启动之前一直存在。即使终止应用程序并在模拟器中重新启动它也无法修复它。解决这个问题的唯一方法(暂时)是完全退出模拟器并重新启动它。

我在 UIViewController 子类中有一个 SKView 子类。 SKView 子类占据 UIViewController 的底部部分，顶部部分包含一些按钮和其他控件。该游戏涉及点击和平移，由 UIGestureControllers 管理，这些 UIGestureControllers 由拥有 SKScene 子类的 SKView 子类拥有。

任意一段时间后，手势就会停止正常工作。在 SKScene 拥有的 View 中，它们都无法正确识别。如果我在 SKView 外部和父 UIViewController 中单击，它们就会出现，但坐标都是错误的。它还会导致状态错误 - 有时 UIPanGestureRecognizer 认为有两根手指按下，而不是只有一根。 UIPanGestureRecognizer 同样处于关闭状态。这种行为没有可识别的模式 - 它只是突然开始。

以下是初始化 SKView 及其场景的相关代码:

    SKView * _gameView = [[SKView alloc] initWithFrame : gameRect];
    _gameView.clipsToBounds = YES;
    // _gameView.scene is an SKScene subclass
    CGSize gameSize = CGSizeMake(_gameView.bounds.size.width,
                                 _gameView.bounds.size.width);
    _scene = [[GameScene alloc] initWithSize : gameSize];
    // Present the scene.
    [_gameView presentScene : _scene];
    [self.view addSubview : _gameView];

以下是 SKScene 子类中注册 UIGestureController 的代码:

- (void) initializeGestureRecognition : (SKView *) view
{
    UIPanGestureRecognizer * panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget : self action : @selector (handlePanGesture:)];
    UITapGestureRecognizer * tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget : self action : @selector (handleTapGesture:)];
    panRecognizer.delegate = self;
    tapRecognizer.delegate = self;
    panRecognizer.maximumNumberOfTouches = 2;
    [tapRecognizer requireGestureRecognizerToFail : panRecognizer];
    [view addGestureRecognizer : panRecognizer];
    [view addGestureRecognizer : tapRecognizer];
}

以下是 UIPanGestureRecognizer 的 handlePanGesture 委托(delegate)的代码:

-(void) handlePanGesture : (UIPanGestureRecognizer*) panRecognizer
{
    self.deltaInView = [panRecognizer translationInView : self.view];
    self.deltaInScene = CGPointMake(deltaInView.x, -(deltaInView.y));
    if (UIGestureRecognizerStateChanged == panRecognizer.state)
        {
            self.panTouchPoint = [self getPanTouchPoint : panRecognizer];
        }
    else if (UIGestureRecognizerStateEnded == panRecognizer.state)
        {
            // Other non-relevant stuff here
        }
}

- (CGPoint) didGetPanTouchPoint : (UIPanGestureRecognizer*) panRecognizer
{
    CGPoint touchPoint = CGPointMake(0.0, 0.0);
    if (2 == panRecognizer.numberOfTouches)
    {
        CGPoint tempPoint = [self calculateSafeCentroidPointFromRecognizer : panRecognizer];
        touchPoint = [self convertPointFromView : tempPoint];
    }
    else if (1 == panRecognizer.numberOfTouches)
    {
        CGPoint tempPoint = [panRecognizer locationOfTouch : 0
                                                    inView : self.view];
        touchPoint = [self convertPointFromView : tempPoint];
    }
    return touchPoint;
}


- (CGPoint) calculateSafeCentroidPointFromRecognizer : (UIGestureRecognizer*) recognizer
{
    CGPoint thisPointInView = [recognizer locationOfTouch : 0
                                                   inView : self.view];
    CGPoint thatPointInView = [recognizer locationOfTouch : 1
                                                   inView : self.view];
    CGPoint safePoint = [self calculateCentroidPoint : thisPointInView
                                         secondPoint : thatPointInView];
    return safePoint;
}


CGPoint CalculateCentroidPoint(const CGPoint * thisPoint,
                               const CGPoint * thatPoint)
{
    CGPoint centroidPoint = CGPointMake((thisPoint->x + thatPoint->x) / 2.0),
                                        (thisPoint->y + thatPoint->y) / 2.0));
    return centroidPoint;
}

以下是 UITapGestureRecognizer 的 handleTapGesture 委托(delegate)的代码:

- (void) handleTapGesture : (UIGestureRecognizer *) gestureRecognizer
{
    if (gestureRecognizer.state == UIGestureRecognizerStateEnded)
    {
        UITapGestureRecognizer * tapRecognizer = (UITapGestureRecognizer*) gestureRecognizer;
        CGPoint viewTouchLocation = [tapRecognizer locationOfTouch : 0
                                                            inView : self.view];
        CGPoint sceneTouchLocation = [self convertPointFromView : viewTouchLocation];
        // Do other stuff here
    }
}

需要注意的一件有趣的事情是，点击和平移手势识别器都不正确。这不是一个或另一个。这让我相信存在一些系统性问题。

(或者，更有可能的是，我搞砸了一些事情。)

有什么想法吗？

Answer 1

有时，模拟器会认为您按住了 Option (⌥) 键并陷入困境，这意味着屏幕上会激活捏合手势助手。要停止此操作，只需再次按 Option。如果这不起作用，请尝试按 Command。