针对特定手势的同时手势识别

Question

我正在尝试启用同步手势识别，但仅针对UIPinchGestureRecognizer和UIRotationGestureRecognizer手势。我不希望它对任何其他手势起作用。如果我将以下属性设置为true，它允许同时识别所有手势，我如何才能将其限制为仅旋转和缩放？

func gestureRecognizer(UIGestureRecognizer, shouldRecognizeSimultaneouslyWithGestureRecognizer: UIGestureRecognizer) -> Bool {
    return true
}

Answer 1

确保您的类实现了UIGestureRecognizerDelegate

class YourViewController: UIViewController, UIGestureRecognizerDelegate ...

将手势的delegate设置为self

yourGesture.delegate = self

将委托函数添加到类中

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    if (gestureRecognizer is UIPanGestureRecognizer || gestureRecognizer is UIRotationGestureRecognizer) {
        return true
    } else {
        return false
    }
}

Answer 2

任何2美分的swift 5.1

//假设您需要优先选择pinch而不是pan：

//UIGestureRecognizerDelegate
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith shouldRecognizeSimultaneouslyWithGestureRecognizer: UIGestureRecognizer) -> Bool {

        if gestureRecognizer is UIPinchGestureRecognizer {
            return true
        }
        return false
    }