ios - How to center a subview -

i adding uiviewcontroller subview uiviewcontroller.

it works great. having hard time trying center subview in middle of parent view.

i read , found 2 lines of code worked other people not working me.

could point out problem??

those are:

popupcontroller.view.center = [self.view convertpoint:self.view.center fromview:self.view.superview];

and

popupcontroller.view.center = cgpointmake(self.view.bounds.size.width / 2, self.view.bounds.size.height / 2); 

parent view controller code:

- (ibaction)selectroutine:(id)sender {     uistoryboard *storyboard = [uistoryboard storyboardwithname:@"storyboard" bundle:nil];      createroutinepopupviewcontroller* popupcontroller = [storyboard instantiateviewcontrollerwithidentifier:@"createroutinepopupview"];    // popupcontroller.view.center = [self.view convertpoint:self.view.center fromview:self.view.superview];     popupcontroller.view.center = cgpointmake(self.view.bounds.size.width / 2, self.view.bounds.size.height / 2);      //tell operating system createroutine view controller     //is becoming child:     [self addchildviewcontroller:popupcontroller];      //add target frame self's view:     [self.view addsubview:popupcontroller.view];      //tell operating system view controller has moved:     [popupcontroller didmovetoparentviewcontroller:self];   } 

child settings

seems reposition view controllers view after centering it. in didmovetoparentviewcontroller:.

move centering code end of selectroutine: method

- (ibaction)selectroutine:(id)sender {     uistoryboard *storyboard = [uistoryboard storyboardwithname:@"storyboard" bundle:nil];      createroutinepopupviewcontroller* popupcontroller = [storyboard instantiateviewcontrollerwithidentifier:@"createroutinepopupview"];      [self addchildviewcontroller:popupcontroller];     [self.view addsubview:popupcontroller.view];     [popupcontroller didmovetoparentviewcontroller:self];      //do centering here     popupcontroller.view.center = [self.view convertpoint:self.view.center fromview:self.view.superview];  } 

or better yet, move didmovetoparentviewcontroller:

- (void)didmovetoparentviewcontroller:(uiviewcontroller *)parent {     //whatever code have here      self.view.center = self.view.superview.center; } 

possibly have modify code bit. i'm problem incorrect (execution-time-wise) placement of centering code - gets subsequently overriden other view-positioning.