Dismiss a UIViewController from bottom to top instead of right to left

I am trying to dismiss a view controller from bottom to top instead of the standard right to left transition. Is this at all开发者_如何学Python possible? Here is the code I have so far:

CGRect screenRect = [[UIScreen mainScreen] applicationFrame];

CGRect endFrame = self.view.frame;
endFrame.origin.y = screenRect.origin.y - screenRect.size.height;

UIView *aView = [[self.view retain] autorelease];
[self.view.window addSubview:aView];
aView.frame = CGRectMake(0, 0, 320, 460);
[UIView animateWithDuration:0.5
                 animations:^{
                     [UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
                     aView.frame = endFrame;
                 }
                 completion:^(BOOL finished) {
                     [self dismissModalViewControllerAnimated:NO];
                     [aView removeFromSuperview];
                 }
 ];

This does result in a transition; but the previous view controller does not appear until after the animation since I can't dismiss until after it completes... any ideas?

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Aah, when you presentModalViewController, it automatically hides the view behind. What you need to do is not present and remove, but add the view controllers view as a subview of the main view. Then you just animate the view offscreen, and removeFromSuperview in the competition handler.