After iOS13, xcode 11 new projects, you will find items more out of SceneDelegatethis class, and then create a new project, run in the simulator no problem, the real machine on 低于iOS13a black screen will appear phone system ( 解决方法就是在AppDelegate.h中按照以前的方法添加一个UIWindow *window的属性即可,因为iOS13以下根本没有UIScene这一层), and then read the code found
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In AppDelegate.hthe less@property (strong, nonatomic) UIWindow * window;
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, AppDelegate.mAlso a little something life-cycle approach
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Introspection SceneDelegatein, windowwas put SceneDelegate.hin, and some of the life cycle ran SceneDelegate.m
#import "SceneDelegate.h"
@interface SceneDelegate ()
@end
@implementation SceneDelegate
- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions {
// Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
// If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
// This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
}
- (void)sceneDidDisconnect:(UIScene *)scene {
// Called as the scene is being released by the system.
// This occurs shortly after the scene enters the background, or when its session is discarded.
// Release any resources associated with this scene that can be re-created the next time the scene connects.
// The scene may re-connect later, as its session was not neccessarily discarded (see `application:didDiscardSceneSessions` instead).
}
- (void)sceneDidBecomeActive:(UIScene *)scene {
// Called when the scene has moved from an inactive state to an active state.
// Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
}
- (void)sceneWillResignActive:(UIScene *)scene {
// Called when the scene will move from an active state to an inactive state.
// This may occur due to temporary interruptions (ex. an incoming phone call).
}
- (void)sceneWillEnterForeground:(UIScene *)scene {
// Called as the scene transitions from the background to the foreground.
// Use this method to undo the changes made on entering the background.
}
- (void)sceneDidEnterBackground:(UIScene *)scene {
// Called as the scene transitions from the foreground to the background.
// Use this method to save data, release shared resources, and store enough scene-specific state information
// to restore the scene back to its current state.
}
@end
Check the information, looked at Apple's documentation know, the original life cycle and ran to the window UIScene to manage, and it appears to the preparation of multi-process iPadOS (App can simultaneously open multiple identical), the logic is now with single or multiple management Appdelegate UIScene, a single or multiple management UIScene UIWindow.
