如何禁用UIScrollView到平移手势识别器？

Question

当平移手势识别器被称为SomePanGestureRecognizer调用时，如何在UIScrollView禁用或强制失败？

gestureRecognizer(_:shouldBeRequiredToFailBy:)方法采用手势识别器参数，而不是平移手势识别器参数，而且我不知道这是为什么无法使其正常工作或由于语法错误。

我有UIScrollView子类，用于强制失败的方法在下面的委托中：

class CustomScrollView: UIScrollView {

    override init(frame: CGRect) {
        super.init(frame: frame)

        configure()

    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        configure()

    }

    private func configure() {

        isScrollEnabled = true
        showsHorizontalScrollIndicator = false
        showsVerticalScrollIndicator = false
        isPagingEnabled = true
        bounces = false
        alwaysBounceVertical = false
        alwaysBounceHorizontal = false

    }

}

// gesture recognizer delegate
extension CustomScrollView: UIGestureRecognizerDelegate {   

    // allow simultaneous gestures
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }

    // force failure
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {

        // TLDR: disable uiscrollview when SomePanGestureRecognizer is called

    }

}

这是平移手势识别器，需要强制UIScrollView的手势识别器失败：

func addSomePanGestureRecognizer() {
    SomePanGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(oneBPanGestureHandler(gesture:)))
    oneBHandle.addGestureRecognizer(SomePanGestureRecognizer)
}

UPDATE我将UIPanGestureRecognizer细分为子类，并使用同时委托使它工作，但是我担心这是一种摇晃的方法，因为我依赖UIKit始终在自定义平移手势之前禁用UIScrollView。

// gesture recognizer delegate
extension CustomScrollView: UIGestureRecognizerDelegate {

    // simultaneous gestures
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {

        if otherGestureRecognizer is CustomPanGestureRecognizer {
            return false
        } else {
            return true
        }

    }

}

更新2这也有效，但我不知道为什么，因为我觉得不应该这样做。 不应该这样吗？

// force failure
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {

    if otherGestureRecognizer is CustomPanGestureRecognizer {
        return true
    } else {
        return false
    }

}

Answer 1

我相信这就是您要寻找的：

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
   let isPanAndOtherRecognizer = gestureRecognizer is UIPanGestureRecognizer && otherGestureRecognizer is SomePanGestureRecognizer
   return !isPanAndOtherRecognizer
}

// force failure
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {

   let isPanAndOtherRecognizer = gestureRecognizer is UIPanGestureRecognizer && otherGestureRecognizer is SomePanGestureRecognizer
   return isPanAndOtherRecognizer
}