// 首先要明確的是,不使用pushViewController的默認動畫,所以在調用這個函數時,要將animated設置爲NO.
// 使用普通的來CATransition實現轉換效果,代碼如下:
CATransition *animation = [CATransition animation];
[animation setDuration:0.3];
[animation setType: kCATransitionMoveIn];
[animation setSubtype: kCATransitionFromTop];
[animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionDefault]];
// [self.navigationController.view.layer addAnimation:animation forKey:nil];