[xib Create Controller]
1. When creating the controller, the parent controller selects a customized controller BaseVC, which inherits from UIViewController.
I checked Create xib, and then when I initialized the controller and pushed, I found that the view in the xib written by this control was not loaded.
My controller was created this way before, but suddenly it didn’t work again. Then I inherited this controller from UIViewController and it can be loaded.

Supplement: The method I use when initializing the controller is XXXVC *vc = [XXXVC new];

                             self.navigationxxx pushViewXXXXX
 我的父类控制器中没有重写 loadView方法。
我之前的控制器创建的方式和上面是一样的，继承的也是BaseVC，初始化后可以加载出来。可是今天突然不行了。想知道是什么原因。我啥都没改过勒