UISwipeGestureRecognizer 导致抖动

Question

我在 UITabBarController 中使用 UISwipeGestureRecogniser:

class TabBarController: UITabBarController {

    override func viewDidLoad() {
        super.viewDidLoad()
        self.selectedIndex = Values.menuSelectedIndex
        let leftSwipe = UISwipeGestureRecognizer(target: self, action: #selector(handleSwipes(_:)))
        let rightSwipe = UISwipeGestureRecognizer(target: self, action: #selector(handleSwipes(_:)))
        leftSwipe.direction = .left
        rightSwipe.direction = .right
        view.addGestureRecognizer(leftSwipe)
        view.addGestureRecognizer(rightSwipe)
    }

    @objc func handleSwipes(_ sender:UISwipeGestureRecognizer) {
        /*if let topController = UIApplication.topViewController() {
            if (topController is HomeVC) {
                if (sender.direction == .left) {
                    self.selectedIndex += 1
                }
                else if (sender.direction == .right) {
                    self.selectedIndex -= 1
                }
            }
        }*/
    }
}

~~当 topController 不是 HomeVC 时，滑动手势应该什么都不做。~~ 不幸的是，左右滚动时会导致抖动。

编辑

UIApplication.topViewController() 是获取当前 UIViewController:

的扩展

extension UIApplication {
    class func topViewController(controller: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
        if let navigationController = controller as? UINavigationController {
            return topViewController(controller: navigationController.visibleViewController)
        }
        if let tabController = controller as? UITabBarController {
            if let selected = tabController.selectedViewController {
                return topViewController(controller: selected)
            }
        }
        if let presented = controller?.presentedViewController {
            return topViewController(controller: presented)
        }
        return controller
    }
}

Answer 1

gestureRecognizer:shouldRecognizeSimultaniouslyWith:otherGesture 对我不起作用，因为我使用的是 NMAMapViewDelegate 和 NMAMapGestureDelegate.

只要在不应该调用 handleSwipes.

的 UIViewController 上删除手势，我就可以轻松完成这项工作

在TabBarController我补充说：

lazy var leftSwipe: UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(handleSwipes(_:)))
lazy var rightSwipe: UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(handleSwipes(_:)))

public func addGestures() {
    view.addGestureRecognizer(leftSwipe)
    view.addGestureRecognizer(rightSwipe)
}

public func removeGestures() {
    view.removeGestureRecognizer(leftSwipe)
    view.removeGestureRecognizer(rightSwipe)
}

并且在任何不应调用 handleSwipes:

的 UIViewControllers 中

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    (navigationController?.tabBarController as? TabBarController)?.removeGestures()
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    (navigationController?.tabBarController as? TabBarController)?.addGestures()
}

UISwipeGestureRecognizer 导致抖动

UISwipeGestureRecognizer causes jerkiness

xcode

gesture

swipe

swift

swift5