全屏返回手势建议直接使用框架
FDFullscreenPopGesture

1.先添加一个代理类

fileprivate class FullscreenPopGestureRecognizerDelegate : NSObject, UIGestureRecognizerDelegate {
    weak var navigationController: UINavigationController!
    func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        guard let gestureRecognizer = gestureRecognizer as? UIPanGestureRecognizer else {
            return false
        }
        if navigationController.viewControllers.count <= 1 {
            return false
        }
        if let _isTransitioning = navigationController.value(forKey: "_isTransitioning") as? Bool, _isTransitioning {
            return false
        }
        let translation = gestureRecognizer.translation(in: gestureRecognizer.view!)
        let isLeftToRight = UIApplication.shared.userInterfaceLayoutDirection == .leftToRight
        let multiplier: CGFloat = isLeftToRight ? 1 : -1;
        if translation.x * multiplier <= 0 {
            return false
        }
        return true
        //可以自己添加某一个控制器的禁止滑动返回手势
    }
}

2.添加全屏手势方法

class MTNavigationController: QMUINavigationController {
    private var fullScreenGesture: UIPanGestureRecognizer!
    private let fullScreenGestureRecognizerDelegate = FullscreenPopGestureRecognizerDelegate()
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Do any additional setup after loading the view.
        addFullScreenGesture()
    }
    
    private func addFullScreenGesture() {
        if fullScreenGesture == nil {
            fullScreenGesture = UIPanGestureRecognizer()
            fullScreenGesture.maximumNumberOfTouches = 1
            fullScreenGestureRecognizerDelegate.navigationController = self
            fullScreenGesture.delegate = fullScreenGestureRecognizerDelegate
            //使用QMUINavigationViewController 时添加
            let qmuiNav_sel = NSSelectorFromString("handleInteractivePopGestureRecognizer:")
            if self.responds(to: qmuiNav_sel) {
                fullScreenGesture.addTarget(self, action: qmuiNav_sel)
            }
        }
        if let sysGes = self.interactivePopGestureRecognizer, let sysV = sysGes.view {
            if !sysV.gestureRecognizers!.contains(fullScreenGesture) {
                if let internalTargets = sysGes.value(forKey: "targets") as? [AnyObject],
                    internalTargets.count > 0,
                    let internalTarget = internalTargets.first!.value(forKey: "target") {
                    sysV.addGestureRecognizer(fullScreenGesture)
                    let internalAction = NSSelectorFromString("handleNavigationTransition:")
                    fullScreenGesture.addTarget(internalTarget, action: internalAction)
                    sysGes.isEnabled = false
                }
            }
        }
    }

}

如果有的控制器里面有横向滚动的ScrollView导致返回手势冲突的，（例如当前页面用了WMPageViewController或者UIPageViewController）再返回时禁用掉当前页面的手势，我这里的判断是：
这个方法[self.panGestureRecognizer translationInView:gestureRecognizer.view].x 的x值，向左滑动是正值，向右滑动是负值，然后再判断当前偏移量

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
    if (gestureRecognizer == self.panGestureRecognizer) {
        BOOL isLeftToRight = [self.panGestureRecognizer translationInView:gestureRecognizer.view].x >= 0;
        if (isLeftToRight && self.contentOffset.x == 0) {
            return NO;
        }
    }
    return YES;
}