改变pushViewController的push方向

CATransition* transition = [CATransition animation];

transition.type = kCATransitionPush;//可更改为其他方式

transition.subtype = kCATransitionFromTop;//可更改为其他方式

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

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