Correct way to disable and enable swipe back for navigation controllers in tab bar controllers

Question

I have a TabBarController with three tabs. The first and last tabs are navigation controllers that I want to have swipe back enabled in. The middle tab is just a standard viewController. By default it seems like swipe back is not enabled. I guess that is because I'm using a back button in these two navigationControllers. I have tried the following code in the root view controllers of the two navigation controllers to enable it:

In viewDidLoad :

self.navigationController?.interactivePopGestureRecognizer?.delegate = self

and conforming to the UIGestureRecognizerDelegate:

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

        if (self.navigationController?.viewControllers.count)! > 1 {
            return true
        }

        return false
    }

The swipe back to work now works however occasionally if one of the view controllers pushes another on top the UI and app will all freeze up. What is the correct way to enable and disable swipe back in Swift?

Answer 1

For people like me who find this 2 years later without an answer

ViewController

In viewDidAppear :

self.navigationController?.interactivePopGestureRecognizer?.delegate = self

and your UIGestureRecognizerDelegate

extension YourViewController: UIGestureRecognizerDelegate {
func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
    if gestureRecognizer.isEqual(navigationController?.interactivePopGestureRecognizer) {
        navigationController?.popViewController(animated: true)
    }
    return false
}

Answer 2

Two steps to achieve this:

1. Add the UIGestureRecognizerDelegate to your class inheritance
2. In viewDidLoad add the following:

To enable swipe back:

navigationController?.interactivePopGestureRecognizer?.isEnabled = true

To disable swipe back:

navigationController?.interactivePopGestureRecognizer?.isEnabled = false