UIScreenEdgePanGestureRecognizer

Question

我正在尝试为我的视图控制器实现屏幕边缘平移手势。但问题是，如果尝试为两个边缘（UIRectEdge.left、UIRectEdge.right）添加边缘平移手势，如

let screenEdgePanGesture = UIScreenEdgePanGestureRecognizer.init(target: self, action: #selector(self.didPanningScreen))
screenEdgePanGesture.edges = [.right, .left]
screenEdgePanGesture.delegate = self
self.view.addGestureRecognizer(screenEdgePanGesture)

选择器方法未调用。但是边缘平移手势适用于一个边缘，即

let screenEdgePanGesture = UIScreenEdgePanGestureRecognizer.init(target: self, action: #selector(self.didPanningScreen))
screenEdgePanGesture.edges = .right
screenEdgePanGesture.delegate = self
self.view.addGestureRecognizer(screenEdgePanGesture)

Answer 1

是的，你是对的，UIScreenEdgePanGestureRecognizer edges是accept/working只有一个值，所以你需要为左右边缘平移创建两个不同的函数。

Swift 4

let screenEdgePanGestureRight = UIScreenEdgePanGestureRecognizer.init(target: self, action: #selector(self.didPanningScreenRight(_:)))
screenEdgePanGestureRight.edges = .right
screenEdgePanGestureRight.delegate = self
self.view.addGestureRecognizer(screenEdgePanGestureRight)

let screenEdgePanGestureLeft = UIScreenEdgePanGestureRecognizer.init(target: self, action: #selector(self.didPanningScreenLeft(_:)))
screenEdgePanGestureLeft.edges = .left
screenEdgePanGestureLeft.delegate = self
self.view.addGestureRecognizer(screenEdgePanGestureLeft)

@objc func didPanningScreenRight(_ recognizer: UIScreenEdgePanGestureRecognizer)  {
    print("Right edge penning")
}

@objc func didPanningScreenLeft(_ recognizer: UIScreenEdgePanGestureRecognizer)  {
    print("Left edge penning")
}