UINavigationController 从上倒下的动画

-(void)transitTo

{

    CATransition *transition = [CATransition animation];

    transition.duration = kAnimationDuration;

    transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; 

    transition.type = kCATransitionPush; 

    transition.subtype = kCATransitionFromTop;

    transitioning = YES;

    transition.delegate = self; 

    [self.navigationController.view.layer addAnimation:transition forKey:nil];

    self.navigationController.navigationBarHidden = NO; 

    [self.navigationController pushViewController:tableViewController animated:NO];

}