objective c - Animate a UINavigationBar's barTintColor -

the app i'm working on changes bartintcolor of navigation bar when pushing new view controllers. right set colour in destination view controller's viewwillappear:method, have few issues that.

with way we're doing right now, navigation bar's colour changes abruptly, while rest of bar content animates usual. i'd bar fade between source , destination colour. there way achieve public cocoa touch apis?

you can add animations match timing , animation curve of view controller transition using uiviewcontrollertransitioncoordinator.

a view controller's transitioncoordinator set after view controller's animation has started (so in viewwillappear of presented view controller). add animations using animatealongsidetransition:completion: on transition coordinator.

an example:

[[self transitioncoordinator] animatealongsidetransition:^(id<uiviewcontrollertransitioncoordinatorcontext> context) {     self.navigationcontroller.navigationbar.translucent = no;     self.navigationcontroller.navigationbar.barstyle = uibarstyleblack;     self.navigationcontroller.navigationbar.tintcolor = [uicolor whitecolor];     self.navigationcontroller.navigationbar.bartintcolor = [uicolor redcolor]; } completion:nil];