After Xcode11, new iOS projects will appear the SceneDelegate file. If the iOS Development Version is lower than iOS 13.0, an error will be reported. Then we should just take it out

Clean up SceneDelegate

1. Kill the scenedelegate. swift file2. Delete the UISceneSession lifecycle methods from the AppDelegate file3. Run the UIScene configuration in info.plist

Settings and views in the AppDelegate

Configure the rootController in the AppDelegate didFinishLaunch as in previous projects, and add the window variable yourself

Okay, let’s start like old times! Ps: If the screen is black, check the backgroundColor of the main view!!