ios - How to access my custom UIPresentationController from within presented controller? -

this how perform transitioning:

extension uiviewcontroller: uiviewcontrollertransitioningdelegate {      public func presentationcontroller(forpresented presented: uiviewcontroller, presenting: uiviewcontroller?, source: uiviewcontroller) -> uipresentationcontroller? {         return overlaypresentationcontroller(presentedviewcontroller: presented, presenting: presenting)     }      func presentoverlaycontroller(_ controller: uiviewcontroller) {          controller.modalpresentationstyle = .custom         controller.transitioningdelegate = self          present(controller, animated: true)     } }  

and within presented controller (alertvc) @ point need access presentation controller:

print(presentationcontroller as? overlaypresentationcontroller) //nil print(presentationcontroller) //is ok, uipresentationcontroller 

why?

presenting:

let controller = alertvc.instantiate() controller.update() presentoverlaycontroller(controller)  class alertvc: uiviewcontroller {      class func instantiate() -> alertvc {         return uistoryboard(name: "alert", bundle: bundle(for: loginvc.classforcoder())).instantiateinitialviewcontroller() as! alertvc     }      func update() {         _ = view          print(presentationcontroller as? overlaypresentationcontroller) //nil     } } 

you view controller presenting current view controller calling presentingviewcontroller

// view controller presented view controller (or farthest ancestor.) self.presentingviewcontroller  

if presenting view controller in navigation controller returns uinavigationcontroller. can view controller need so:

let presentingnvc = self.presentingviewcontroller as? uinavigationviewcontroller let neededvc = presentingnvc.viewcontrollers.last as? neededviewcontroller