Define A Marco with API Check(safeAreaInsets only available in iOS 11.0 or newer)
工程中有这样的一个宏定义:defineSafeAreaInsets[UIApplicationsharedApplication].delegate.window.safeAreaInsets对它的使用引起了警告:safeAreaInsetsonlyavailableiniOS11.0ornewer查到这篇有用的帖子:https://stackoverflow.com/questions/4759