Xcode 26还没有适配SceneDelegate的app建议尽早适配

Xcode 26之前不需要多窗口的很多app没有适配SceneDelegate，升级到Xcode 26后运行没有问题，但是控制台有以下输出：

swift 复制代码

`UIScene` lifecycle will soon be required. Failure to adopt will result in an assert in the future.

UIApplicationDelegate 中的相关生命周期函数也有弃用标记：

scss 复制代码

/// Tells the delegate that the application has become active 
/// - Note: This method is not called if `UIScene` lifecycle has been adopted. 
- (void)applicationDidBecomeActive:(UIApplication *)application API_DEPRECATED("Use UIScene lifecycle and sceneDidBecomeActive(_:) from UISceneDelegate or the UIApplication.didBecomeActiveNotification instead.", ios(2.0, 26.0), tvos(9.0, 26.0), visionos(1.0, 26.0)) API_UNAVAILABLE(watchos);

建议尽早适配

方案举例

以下是我的适配方案，供大家参考

兼容iOS13以下版本；
app只有单窗口场景。

1. 配置Info.plist

Delegate Class Name和Configuration Name 可自定义

2. 配置SceneDelegate

创建SceneDelegate class 类名要和Info.plist中配置一致

appDelegate中实现代理

objectivec 复制代码

- (UISceneConfiguration *)application:(UIApplication *)application configurationForConnectingSceneSession:(UISceneSession *)connectingSceneSession options:(UISceneConnectionOptions *)options  API_AVAILABLE(ios(13.0)){
   //  name要和Info.plist中配置一致
  return [[UISceneConfiguration alloc] initWithName:@"Default Configuration" sessionRole:connectingSceneSession.role];
}

- (void)application:(UIApplication *)application didDiscardSceneSessions:(NSSet<UISceneSession *> *)sceneSessions  API_AVAILABLE(ios(13.0)){
  // 释放资源，单窗口app不用关注
}

3. 新建单例 AppLifecycleHelper 实现AppDelegate和SceneDelgate共享的方法

iOS 13 及以上需要在scene: willConnectToSession: options: 方法中创建Window，之前仍然在 didFinishLaunchingWithOptions:

AppDelegate:

less 复制代码

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [AppLifecycleHelper sharedInstance].launchOptions = launchOptions;
     // ... 自定义逻辑
    if (@available(iOS 13, *)) {
 
    } else {
        [[AppLifecycleHelper sharedInstance] createKeyWindow];
    }
}

SceneDelgate:

URL冷启动APP时不调用openURLContexts方法，这里保存URL在DidBecomeActive处理

objectivec 复制代码

- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions  API_AVAILABLE(ios(13.0)){
    [[AppLifecycleHelper sharedInstance] createKeyWindowWithScene:(UIWindowScene *)scene];
    // 通过url冷启动app，一般只有一个url 
    for (UIOpenURLContext *context **in** connectionOptions.URLContexts) {
        NSURL *URL = context.URL;
        if (URL && URL.absoluteString.length > 0) {
            self.launchUrl = URL;
        }
    }
}

AppLifecycleHelper:

AppLifecycleHelper 复制代码

- (void)createKeyWindow {
    UIWindow *window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
    [self setupMainWindow:window];
}

- (void)createKeyWindowWithScene:(UIWindowScene *)scene API_AVAILABLE(ios(13.0)) {
    UIWindow *window = [[UIWindow alloc] initWithWindowScene:scene];
    [self setupMainWindow:window];
}

- (void)setupMainWindow:(UIWindow *)window {
}

实现SceneDelegate后appDelegate 中失效的方法

在AppLifecycleHelper中实现，共享给两个DelegateClass

AppDelegate 复制代码

- (void)applicationDidBecomeActive:(UIApplication *)application {
    [[AppLifecycleHelper sharedInstance] appDidBecomeActive];
}

- (void)applicationWillResignActive:(UIApplication *)application {

}

- (void)applicationDidEnterBackground:(UIApplication *)application {

}

- (void)applicationWillEnterForeground:(UIApplication *)application {

}
  
 /// URL Scheme
- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url options:(NSDictionary<UIApplicationOpenURLOptionsKey, **id**> *)options {

}

/// 接力用户活动
- (BOOL)application:(UIApplication *)application continueUserActivity:(NSUserActivity *)userActivity restorationHandler:(void (^)(NSArray<**id**<UIUserActivityRestoring>> * _Nullable))restorationHandler {

}

/// 快捷方式点击
- (void)application:(UIApplication *)application performActionForShortcutItem:(UIApplicationShortcutItem *)shortcutItem completionHandler:(void (^)(BOOL))completionHandler API_AVAILABLE(ios(9.0)) {
}

SceneDelegate部分代码示例：

SceneDelegate 复制代码

- (void)sceneDidBecomeActive:(UIScene *)scene  API_AVAILABLE(ios(13.0)){
    [[AppLifecycleHelper sharedInstance] appDidBecomeActiveWithLaunchUrl:self.launchUrl];
    // 清空冷启动时的url
    self.launchUrl = nil;
}

这个方法总结下来就是求同存异，由Helper提供SceneDelegate与AppDelegate相同或类似的方法，适合单窗口、且支持iOS 13以下的app；

另外注意URL Scheme冷启动app不会执行openURL需要记录URL，在合适的时机（一般是DidBecomeActive）处理。