ios - Custom transition from a VC to another VC inside a view -

i have code changes vc vc inside view (containerview). code works, how set transition between both views?

var childvc: uiviewcontroller? @iboutlet weak var containerview: uiview!  func changeviewcontroller() {      childvc?.willmovetoparentviewcontroller(nil)     childvc?.view.removefromsuperview()     childvc?.removefromparentviewcontroller()     childvc = storyboard?.instantiateviewcontrollerwithidentifier("identifier") as? uiviewcontroller     if let childvc = childvc {         addchildviewcontroller(childvc)         childvc.view.frame = containerview.bounds          containerview.addsubview(childvc.view)         childvc.didmovetoparentviewcontroller(self)     } } 

i tried, didnt work:

let oldview = childvc?.view uiview.transitionfromview(oldview!, toview: childvc.view, duration: 2, options: uiviewanimationoptions.transitionflipfromleft, completion: { (succeed) -> void in          }) 

to transition between vcs, can display each vc in view , animate them in , out of view in container view. along these lines:

[uiview beginanimations:nil context:null]; [uiview setanimationduration:1.0]; [uiview setanimationdelegate:self.containerview];  // animations here  [uiview commitanimations];