ios - Custom Unwind Segue Crashes with NSException in Swift -

i have unwind segue have custom animation.

i have custom segue class:

import uikit import quartzcore  class seguefromright: uistoryboardsegue {  override func perform() {     let src: uiviewcontroller = self.source     let dst: uiviewcontroller = self.destination     let transition: catransition = catransition()     let timefunc : camediatimingfunction = camediatimingfunction(name: kcamediatimingfunctioneaseineaseout)     transition.duration = 0.25     transition.timingfunction = timefunc     transition.type = kcatransitionpush     transition.subtype = kcatransitionfromright     src.navigationcontroller!.view.layer.add(transition, forkey: kcatransition)     src.navigationcontroller!.pushviewcontroller(dst, animated: false)     } } 

i have defined unwind segue:

@ibaction func unwindtogameover(sender: uistoryboardsegue) { } 

i call segue on button press:

@ibaction func backbuttonpressed(_ sender: any) {     performsegue(withidentifier: "unwindtogameover", sender: self) } 

here's interface builder unwind segue:

it crashes "terminating uncaught exception of type nsexception"

the custom segue works on show segue & unwind segue works when remove class.

any ideas?

you're using unwind segue , custom segue pushing. unwind segue in navigation controller pop, not push.

frankly, nowadays you'd use custom transitions, rather subclassing segue, if change pop, works.

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