iOS navigationController push动画

提供一个简单的实现方式，代码如下：

- (void)push {

        TestViewController *vc = [[TestViewController alloc] init];
        vc.view.backgroundColor = [UIColor redColor];
        CATransition* transition = [CATransition animation];
        transition.duration =0.4f;
        transition.type = kCATransitionMoveIn;
        transition.subtype = kCATransitionFromTop;
        [self.navigationController.view.layer addAnimation:transition forKey:kCATransition];
        [self.navigationController pushViewController:vc animated:NO];
    }

    - (void)pop {

        CATransition* transition = [CATransition animation];
        transition.duration =0.4f;
        transition.type = kCATransitionReveal;
        transition.subtype = kCATransitionFromBottom;
        [self.navigationController.view.layer addAnimation:transition forKey:kCATransition];
        [self.navigationController popViewControllerAnimated:NO];
    }