with Navigation controller, if you want implement swipe interaction to popup view to previous view, you can:
1. add swipe gesture onto the second view:
2. set the gesture to "right":
3.to handle the swipe action, there are two ways:
first solution: (swipe action)
second solution: (gesture delegate)
You don't have to implement UIGestureRecognizerDelegate, IOS will still call gesture delegate functions.
there are several function of this delegate you can use, I don't know which is the right one. please read the api doc. But my code works.
So my personal recommendation is the first solution.