When your app’s state changes, UIKit notifies you by calling methods of the appropriate delegate object:
In iOS 13 and later, use UISceneDelegate objects to respond to life-cycle events in a scene-based app.
In iOS 12 and earlier, use the UIApplicationDelegate object to respond to life-cycle events.
Note:
If you enable scene support in your app, iOS always uses your scene delegates in iOS 13 and later. In iOS 12 and earlier, the system uses your app delegate.
回调不一样了,所以么有对应处理,就变成 app 都重新启动那样子了? 其实就是 iOS 13 的适配问题?