swift - 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，但仅限于 UIPinchGestureRecognizer 和 UIRotationGestureRecognizer 手势。我不希望它适用于任何其他手势。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

确保你的类实现了UIGestureRecognizerDelegate

class YourViewController: UIViewController, UIGestureRecognizerDelegate ...

---

设置手势的delegate为self

yourGesture.delegate = self

---

在你的类中添加委托(delegate)函数

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