如何在 UINavigationController 中设置 left BarButtonItem 后启用向后/向左滑动手势？

我从 给你得到了相反的问题。 在 iOS7默认情况下，UINavigationController堆栈的后滑动姿态可以弹出现在的 ViewController。现在我只是制服所有的 self.navigationItem.leftBarButtonItem风格的所有 ViewControllers。

密码如下:

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

在此之后，navigationController.interactivePopGestureRecognizer就被禁用了。如何在不删除自定义 leftBarButtonItem的情况下启用流行手势？

谢谢！

132019 次浏览
小开
最佳答案

First set delegate in viewDidLoad:

self.navigationController.interactivePopGestureRecognizer.delegate = self;

And then disable gesture when pushing:

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

And enable in viewDidDisappear:

self.navigationController.interactivePopGestureRecognizer.enabled = YES;

Also, add UINavigationControllerDelegate to your view controller.

小开

It works for me when I set the delegate

self.navigationController.interactivePopGestureRecognizer.delegate = self;

and then implement

Swift

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

Objective-C

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldBeRequiredToFailByGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
小开

Setting a custom back button disable the swipe back feature.

The best thing to do to keep it is to subclass UINavigationViewController and set itself as the interactivePopGestureRecognizer delegate; then you can return YES from gestureRecognizerShouldBegin to allow the swipe back.

For example, this is done in AHKNavigationController

And a Swift version here: https://stackoverflow.com/a/43433530/308315

小开

it works for me Swift 3:

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

and in ViewDidLoad:

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

Swift 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)
}
小开

This is the best way to enable/ disable swipe to pop view controller in iOS 10, Swift 3 :

For First Screen [ Where you want to Disable Swipe gesture ] : 

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
} }

For middle screen [ Where you want to Enable Swipe gesture ] :

class FriendListViewController : UIViewController {


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


super.viewDidLoad()
swipeToPop()
}


func swipeToPop() {


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

You need to handle two scenarios:

  1. When you're pushing a new view onto the stack
  2. When you're showing the root view controller

If you just need a base class you can use, here's a Swift 3 version:

import UIKit


final class SwipeNavigationController: UINavigationController {
    

// MARK: - Lifecycle
    

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


delegate = self
}
    

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
}
}

If you end up needing to act as a UINavigationControllerDelegate in another class, you can write a delegate forwarder similar to this answer.

Adapted from source in Objective-C: https://github.com/fastred/AHKNavigationController

小开

For those who are still having trouble with this, try separating the two lines as below.

override func viewDidLoad() {
self.navigationController!.interactivePopGestureRecognizer!.delegate = self
...


override func viewWillAppear(_ animated: Bool) {
self.navigationController!.interactivePopGestureRecognizer!.isEnabled = true
...

Obviously, in my app,

interactivePopGestureRecognizer!.isEnabled

got reset to false before the view was shown for some reason.

小开

This answer, but with storyboard support.

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)


self.setup()
}


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


self.setup()
}


private func setup() {
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
}
小开

I did not need to add gestureRecognizer functions for it. It was enough for me to add following code blocks at viewDidLoad:

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

In Swift you can do the following code

import UIKit
extension UINavigationController: UIGestureRecognizerDelegate {


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


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

Above code helps in swift left to go back to previous controller like Facebook, Twitter.

小开

If you want this behaviour everywhere in your app and don't want to add anything to individual viewDidAppear etc. then you should create a subclass

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
}


}

Now, whenever you use QFNavigationController you get the desired experience.

小开

We're all working around some old bugs that haven't been fixed likely because it's "by design." I ran into the freezing problem @iwasrobbed described elsewhere when trying to nil the interactivePopGestureRecognizer's delegate which seemed like it should've worked. If you want swipe behavior reconsider using backBarButtonItem which you can customize.

I also ran into interactivePopGestureRecognizer not working when the UINavigationBar is hidden. If hiding the navigation bar is a concern for you, reconsider your design before implementing a workaround for a bug.

小开

Most answers are pertaining to doing it on code. But I'll give you one that works on Storyboard. Yes! You read it right.

  • Click on main UINavigationController and navigate to it's Identity Inspector tab.

  • Under User Defined Runtime Attributes, set a single runtime property called interactivePopGestureRecognizer.enabled to true. Or graphically, you'd have to enable the checkbox as shown in the image below.

That's it. You're good to go. Your back gesture will work as if it was there all along.

Image displaying the property that out to be set

小开

Swift 5, add only these two in viewDidLoad method:

override func viewDidLoad() {
super.viewDidLoad()


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

I was having issue to enable and disable swipe interaction to pop viewcontrollers.

I have a base navigation controller and my app flow is like push Splash VC, push Main VC, and then push Some VC like that.

I want swipe to go back from Some VC to Main VC. Also disable swipe to prevent going back to splash from main VC.

After some tryings below works for me.

  1. Write an extension in Main VC to disable swipe
extension MainViewController : UIGestureRecognizerDelegate{
    

func disableSwipeToPop() {
self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true
self.navigationController?.interactivePopGestureRecognizer?.delegate = self
}
    

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

if gestureRecognizer == self.navigationController?.interactivePopGestureRecognizer {
return false
}
return true
}
}
  1. Call disableSwipeToPop() method on viewDidAppear of Main VC
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
self.disableSwipeToPop()
}
  1. Write an extension in Some VC to enable swipe to pop Some VC
extension SomeViewController{
    

func enableSwipeToPop() {
self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true
self.navigationController?.interactivePopGestureRecognizer?.delegate = nil
}
    

}
  1. Call enableSwipeToPop() method on viewDidLoad of Some VC
override func viewDidLoad() {
super.viewDidLoad()
self.enableSwipeToPop()
}

That's it. Also if you try to disable swipe on viewWillAppear, you may loose the ability to swipe again when user stops swiping to cancel the action.

小开

I've created the following Swift 5+ UIViewController extension to make it easier to add/remove the interactive pop gesture on each screen that you need it on.

Note:

  • Add enableInteractivePopGesture() on each screen that has your custom back button

  • Add disableInteractivePopGesture() on viewDidAppear for root screen of your navigation controller to prevent the swipe back issue some of the answers here mention

  • Also add disableInteractivePopGesture() on pushed screens that you don't want to have the back button and swipe back gesture

    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
}
}

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