UISwipeGestureRecognizer 不适用于呈现的 VC 和视图

Question

层次结构：

MainVC 调用 present(GameVC, animated: true, completion: nil)

let vc = self.storyboard?.instantiateViewController(withIdentifier: "GameVC") as! GameVC self.present(vc, animated: true, completion: nil)
GameVC 有 GameView（UIView 的子类），涵盖整个 VC

在 GameView 的 初始化器中，我有这段代码来配置滑动手势：

let leftGesture = UISwipeGestureRecognizer(target: self, action: #selector(leftSwipe)) leftGesture.direction = .left self.addGestureRecognizer(leftGesture) let rightGesture = UISwipeGestureRecognizer(target: self, action: #selector(rightSwipe)) rightGesture.direction = .right self.addGestureRecognizer(rightGesture) let downGesture = UISwipeGestureRecognizer(target: self, action: #selector(downSwipe)) downGesture.direction = .down self.addGestureRecognizer(downGesture)

对应的选择器：

@objc func downSwipe() { //code } @objc func leftSwipe() { //code } @objc func rightSwipe() { //code }

没有调用选择器。但是，当我将 GameVC 设置为正在显示的初始 VC 时（通过将故事板箭头拖到 GameVC 上）， 手势按预期工作。 这让我觉得调用 present() 可能会弄乱手势操作的层次结构，但我不太确定。

Answer 1

你必须说明你的手势可以通过提供相应的委托方法来同时处理。

下面的演示代码可以使用上面的代码。使用 Xcode 11.4 / iOS 13.4

测试

class GameView: UIView {
}

// in Storyboard just empty view of above custom GameView
class GameVC: UIViewController, UIGestureRecognizerDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()

        let leftGesture = UISwipeGestureRecognizer(target: self, action: #selector(leftSwipe))
        leftGesture.direction = .left
        leftGesture.delegate = self
        self.view.addGestureRecognizer(leftGesture)

        let rightGesture = UISwipeGestureRecognizer(target: self, action: #selector(rightSwipe))
        rightGesture.direction = .right
        rightGesture.delegate = self
        self.view.addGestureRecognizer(rightGesture)

        let downGesture = UISwipeGestureRecognizer(target: self, action: #selector(downSwipe))
        downGesture.direction = .down
        downGesture.delegate = self
        self.view.addGestureRecognizer(downGesture)

    }

    // allows own view gestures to run with system originated simultaneously
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        true
    }

    @objc func downSwipe() {
        print(">> down swipe")
    }

    @objc func leftSwipe() {
        print(">> left swipe")
    }

    @objc func rightSwipe() {
        print(">> right swipe")
    }
}

// Initial VC, in storyboard contains only button linked to below showGame action
class ViewController: UIViewController {

    @IBAction func showGame(_ sender: Any) {
        let vc = self.storyboard?.instantiateViewController(withIdentifier: "GameVC") as! GameVC
        self.present(vc, animated: true, completion: nil)
    }
}

UISwipeGestureRecognizer 不适用于呈现的 VC 和视图

UISwipeGestureRecognizer doesn't work on presented VC and view

selector

ios

uiswipegesturerecognizer

presentviewcontroller

swift