ios - UIImagepicker navigates to superview not to the subview containing UIimagpicker -

on viewcontrollera have added few uiviews , viewcontrollerb's view asubview. viewcontrollerb has imagepicker. after picking image navigates viewcontrollera. how can return viewcontrollerb without disturbing other views?

-(void)changeimage:(id)sender {uiimagepickercontroller *picker=[[uiimagepickercontroller alloc]init];      picker.delegate=self;      picker.allowsediting=yes;     picker.sourcetype=uiimagepickercontrollersourcetypecamera;      [self presentviewcontroller:picker animated:yes completion:null];      }  

add viewcontroller b viewcontroller a. in vc a:

swift 3:

instanceofvcb.willmove(toparentviewcontroller: self) addchildviewcontroller(instanceofvcb) view.addsubview(instanceofvcb.view) // add desired contraints instanceofvcb.view instanceofvcb.didmove(toparentviewcontroller: self) 

obj-c:

[instanceofvcb willmovetoparentviewcontroller: self]; [self addchildviewcontroller: instanceofvcb]; [self.view addsubview: instanceofvcb.view]; // add desired contraints instanceofvcb.view; [instanceofvcb didmovetoparentviewcontroller: self];