如何在设置leftBarButtonItem后在UINavigationController中启用后退/左侧滑动手势？

Question

我从这里得到了相反的问题.默认情况下iOS7,UINavigationController堆栈的后滑动手势可以弹出呈现的内容ViewController.现在我只是穿着所有self.navigationItem.leftBarButtonItem风格的制服ViewControllers.

这是代码:

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithImage:LOADIMAGE(@"back_button") style:UIBarButtonItemStylePlain target:self action:@selector(popCurrentViewController)];

之后,navigationController.interactivePopGestureRecognizer被禁用.如何在不删除自定义的情况下启用弹出手势leftBarButtonItem？

谢谢!

Answer 1

首先在viewDidLoad中设置委托:

self.navigationController.interactivePopGestureRecognizer.delegate = self;

然后在推送时禁用手势:

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated {
    [super pushViewController:viewController animated:animated];
    self.interactivePopGestureRecognizer.enabled = NO;
}

并在viewDidDisappear中启用:

self.navigationController.interactivePopGestureRecognizer.enabled = YES;

此外,添加UINavigationControllerDelegate到您的视图控制器.

Answer 2

您需要处理两种情况:

1. 当您将新视图推入堆栈时
2. 当您显示根视图控制器时

如果您只需要一个可以使用的基类,这里是一个Swift 3版本:

import UIKit

final class SwipeNavigationController: UINavigationController {

    // MARK: - Lifecycle

    override init(rootViewController: UIViewController) {
        super.init(rootViewController: rootViewController)
    }

    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)

        delegate = self
    }

    required init?(coder aDecoder: NSCoder) { 
        super.init(coder: aDecoder) 

        delegate = self 
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // This needs to be in here, not in init
        interactivePopGestureRecognizer?.delegate = self
    }

    deinit {
        delegate = nil
        interactivePopGestureRecognizer?.delegate = nil
    }

    // MARK: - Overrides

    override func pushViewController(_ viewController: UIViewController, animated: Bool) {
        duringPushAnimation = true

        super.pushViewController(viewController, animated: animated)
    }

    // MARK: - Private Properties

    fileprivate var duringPushAnimation = false

}

// MARK: - UINavigationControllerDelegate

extension SwipeNavigationController: UINavigationControllerDelegate {

    func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {
        guard let swipeNavigationController = navigationController as? SwipeNavigationController else { return }

        swipeNavigationController.duringPushAnimation = false
    }

}

// MARK: - UIGestureRecognizerDelegate

extension SwipeNavigationController: UIGestureRecognizerDelegate {

    func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        guard gestureRecognizer == interactivePopGestureRecognizer else {
            return true // default value
        }

        // Disable pop gesture in two situations:
        // 1) when the pop animation is in progress
        // 2) when user swipes quickly a couple of times and animations don't have time to be performed
        return viewControllers.count > 1 && duringPushAnimation == false
    }
}

如果您最终需要UINavigationControllerDelegate在另一个类中执行操作,则可以编写类似于此答案的委托转发器.

改编自Objective-C中的源代码:https://github.com/fastred/AHKNavigationController

Answer 3

当我设置委托时,它适用于我

self.navigationController.interactivePopGestureRecognizer.delegate = self;

然后实施

extension MyViewController:UIGestureRecognizerDelegate {
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }
}

Answer 4

它适用于我Swift 3:

    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }

并在ViewDidLoad中:

    self.navigationController?.interactivePopGestureRecognizer?.delegate = self
    self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true

Answer 5

这是在iOS 10,Swift 3中启用/禁用滑动到弹出视图控制器的最佳方法:

对于第一个屏幕[您要禁用滑动手势的位置]:

class SignUpViewController : UIViewController,UIGestureRecognizerDelegate {

//MARK: - View initializers
override func viewDidLoad() {
    super.viewDidLoad()
}

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    swipeToPop()
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

func swipeToPop() {

    self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true;
    self.navigationController?.interactivePopGestureRecognizer?.delegate = self;
}

func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {

    if gestureRecognizer == self.navigationController?.interactivePopGestureRecognizer {
        return false
    }
    return true
} }

对于中间屏幕[您要在其中启用滑动手势]:

class FriendListViewController : UIViewController {

//MARK: - View initializers
override func viewDidLoad() {

    super.viewDidLoad()
    swipeToPop()
}

func swipeToPop() {

    self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true;
    self.navigationController?.interactivePopGestureRecognizer?.delegate = nil;
} }

Answer 6

我不需要为它添加gestureRecognizer 函数。我在 viewDidLoad 中添加以下代码块就足够了：

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationController?.interactivePopGestureRecognizer?.delegate = nil
    self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true
}

Answer 7

斯威夫特 3：

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    self.navigationController?.interactivePopGestureRecognizer?.delegate = self
}

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    return true
}

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    return (otherGestureRecognizer is UIScreenEdgePanGestureRecognizer)
}

Answer 8

在 Swift 中，您可以执行以下代码

import UIKit
extension UINavigationController: UIGestureRecognizerDelegate {

    open override func viewDidLoad() {
        super.viewDidLoad()
        interactivePopGestureRecognizer?.delegate = self
    }

    public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        return viewControllers.count > 1
    }
}

上面的代码有助于快速向左返回以前的控制器，如 Facebook、Twitter。

Answer 9

如果您希望在您的应用程序中随处可见这种行为，并且不想向个人viewDidAppear等添加任何内容，那么您应该创建一个子类

class QFNavigationController:UINavigationController, UIGestureRecognizerDelegate, UINavigationControllerDelegate{
    override func viewDidLoad() {
        super.viewDidLoad()
        interactivePopGestureRecognizer?.delegate = self
        delegate = self
    }

    override func pushViewController(_ viewController: UIViewController, animated: Bool) {
        super.pushViewController(viewController, animated: animated)
        interactivePopGestureRecognizer?.isEnabled = false
    }

    func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {
        interactivePopGestureRecognizer?.isEnabled = true
    }

    // IMPORTANT: without this if you attempt swipe on
    // first view controller you may be unable to push the next one
    func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        return viewControllers.count > 1
    }

}

现在，无论何时使用，QFNavigationController您都会获得所需的体验。

Answer 10

我创建了以下Swift 5+ UIViewController扩展，以便更轻松地在您需要的每个屏幕上添加/删除交互式弹出手势。

笔记：

• 添加enableInteractivePopGesture()到每个具有自定义后退按钮的屏幕上

• 添加导航控制器的根屏幕disableInteractivePopGesture()，viewDidAppear以防止向后滑动问题这里提到的一些答案

• 还disableInteractivePopGesture()可以在您不希望有后退按钮和向后滑动手势的推送屏幕上添加

  extension UIViewController: UIGestureRecognizerDelegate {
  
    func disableInteractivePopGesture() {
      navigationItem.hidesBackButton = true
      navigationController?.interactivePopGestureRecognizer?.delegate = self
      navigationController?.interactivePopGestureRecognizer?.isEnabled = false
    }
  
    func enableInteractivePopGesture() {
      navigationController?.interactivePopGestureRecognizer?.delegate = self
      navigationController?.interactivePopGestureRecognizer?.isEnabled = true
    }
  }