在切换到tab Bar控制器Swift中的另一个选项卡后，如何保持ViewController细节不变

I am having trouble with my Tab Bar Controller. On tab 1 I have a map. The map is on auto layout to fill approximately half of the screen. I have an option to make the map full screen. If I were to make the map full screen, go to tab 2 and return to tab 1, the map will be back in its auto layout position. In this case, I would need it to be full screen.I am having trouble with my Tab Bar Controller.