如何使用Tab Bar管理的视图平滑地进/出，而不是几乎不进/出闪烁？

I have an Tab Bar controller and a nice tab bar on the bottom of my app. There are three buttons. When I tap one, then the view controller from that tab bar is "invoked" and the new view appears immediately. That's like banging a door very hard, so that everyone in the neighbourhood can hear it. I would like to have a softer transition, if possible. Something like fading out, fading in, or page flip transition. What do I have to look at to do this?I have an Tab Bar controller and a nice tab bar