iOS UIView过渡不顺畅？

Question

我使用以下代码在转换期间显示动画：

CATransition *animation = [CATransition animation];
[animation setDuration:0.4];
[animation setType:kCATransitionPush];
[animation setSubtype:kCATransitionFromTop];
[animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
[[newPage.view layer] addAnimation:animation forKey:@"SwitchToView1"];

但过渡似乎并不像我看到的其他应用程序那样顺畅。有谁知道为什么它不顺畅？谢谢！