So iOS 7 introduced this new feature that you can pop a view controller by panning on the left edge. Here is my problem: I have two view controllers, A and B, that are connected by a push segue. Both of the controllers have navigation bars (by embedding A in a navigation controller). The navigation bar in B will be hidden once the user enters B's scene, and can be shown if the user taps on the scene. If the user pans on the left edge of B while the navigation bar is hidden, the navigation bar in A will be hidden as well, which means that there is no way for the user to return further back from A. So is there a way to enforce A to always show the navigation bar regardless of B has hidden the bar or not? Or is there a easy way to prevent the pan gesture from taking effect? I read [this post](https://stackoverflow.com/questions/18975060/prevent-ios7-pan-gesture-to-pop-view-controller) which suggested a way of preventing the pan, but I can't locate the property in storyboard.

**EDIT:** So I disabled the interactive pop gesture recognizer but that only solved half of the problem. The other half is that if I click the back button on the child view controller navigation bar when the navigation bar is disappearing, I am navigated back to the parent view controller without a navigation bar. I tried calling `[self.navigationController setNavigationBarHidden:NO]` in `viewWillAppear` and then `viewDidLoad` but it does not work. Is this some sort of bug in the SDK or am I missing something?

Here is the code for hiding the navigation bar in the child view controller

```
- (void)hideNavigationBar
{
    if (self.navigationBarHidden == NO)
    {
        [UIView animateWithDuration:UINavigationControllerHideShowBarDuration animations:^{
            self.navigationController.navigationBar.alpha = 0.0;
            self.previewCollectionView.alpha = 0.0;
        } completion:^(BOOL finished) {
            self.navigationBarHidden = YES;
        }];
    }
}

```