//由于音视频聊天里头有音频和视频聊天界面的切换，直接用present的话页面过渡会不太自然，这里还是用push，然后做出present的效果
AudioChatViewController *vc = [[AudioChatViewController alloc] init];
CATransition *transition = [CATransition animation];
transition.duration = 0.25;
transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionDefault];
transition.type = kCATransitionPush;
transition.subtype = kCATransitionFromTop;
[self.navigationController.view.layer addAnimation:transition forKey:nil];
self.navigationController.navigationBarHidden = YES;
[self.navigationController pushViewController:vc animated:NO];
