ios - Can I set maximum alpha for CATransition? -

is possible adjust maximum alpha (opacity) in catransition when views fade in , out?

what want looks modal segue. compared default modal segue, transition given catransition «dramatic».

say have 2 views. a: view want transition from. b: view want transition to.

i want b come moving in bottom on a. use kcatransitionmovein type, subtype kcatransitionfromtop (which weird because b moving bottom, not top).

in default modal segue, works fine, , greyed out little. catransition, totally black @ towards end of transition when b has moved 70% on a.

code:

uistoryboard *loginboard = [uistoryboard storyboardwithname:@"login" bundle:nil]; uiviewcontroller *vc = [loginboard instantiateinitialviewcontroller];  uiwindow *keywindow = [[[uiapplication sharedapplication] delegate] window];  [keywindow insertsubview:vc.view belowsubview:keywindow.rootviewcontroller.view];  catransition *transition = [catransition animation]; transition.duration = 0.5; transition.type = kcatransitionmovein; transition.subtype = kcatransitionfromtop;  [keywindow.layer addanimation:transition forkey:kcatransition];  [keywindow.rootviewcontroller.view removefromsuperview]; keywindow.rootviewcontroller = vc; 

the problem originates here.

after digging around more figured can't set maximum opacity / alpha catransition out of box.

so solved this:

//offset frame vc.view.frame = cgrectmake(0, cgrectgetheight(self.view.bounds), cgrectgetwidth(self.view.bounds), cgrectgetheight(self.view.bounds)); [uiview animatewithduration:5      animations:^{          //insert over/before root view instead of after          [keywindow insertsubview:vc.view abovesubview:keywindow.rootviewcontroller.view];          vc.view.frame = cgrectmake(0, 0, cgrectgetwidth(self.view.bounds), cgrectgetheight(self.view.bounds));          keywindow.rootviewcontroller.view.alpha = 0.8;      }      completion:^(bool finished) {          nslog(@"completed! can change rootviewcontroller etc..");      }];