单击标签栏控制器时如何获取导航栏？

I have an application in which I am trying to dynamically switch the tabbar tab through the code. The tab switches properly. When I click on any tab the didSelectController method of the tab is called and my problem is when I click on any tab the tab on which I am performing switching of views, its navigation bar disappears and its tabbar image and title also disappears.I have an application in which I am trying to d