xcode 11 APPdelegate适配ios9

如果我们不开发iPadOS多窗口APP，SceneDelegate窗口管理我们可以不需要直接删掉就好了。

1. 删除掉info.plist中Application Scene Manifest选项，同时，文件SceneDelegate可删除可不删

相关代码注释

	func application(_ application: UIApplication, 	configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {
        return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
    }

    func application(_ application: UIApplication, didDiscardSceneSessions sceneSessions: Set) {
    }
    //注释掉这两个方法。

如果我们开发iPadOS多窗口APP，SceneDelegate窗口管理我们可以不需要直接删掉就好了。

    1.如果系统是ios13以下的，直接在APPdelegate中进行判断，因为ios13，APPdelegate中没有window属性，需要重新添加window属性，创建window

if (@available(ios 13, *)) {
        
    }else{
        self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
        
        [self detectNetwork];

        CLTabbarController *tabbarVC = [[CLTabbarController alloc]init];
        CLBaseNavigationController *baseVC = [[CLBaseNavigationController alloc]initWithRootViewController:tabbarVC];
        self.window.rootViewController = baseVC;
        
        [self.window makeKeyAndVisible];

    }

xcode11新增了SceneDelegate 方法

如果是ios13系统，系统走以下方法

- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions  API_AVAILABLE(ios(13.0)){
    // 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).
    
    [self detectNetwork];

    UIWindowScene *windowScene = (UIWindowScene *)scene;
    self.window = [[UIWindow alloc] initWithWindowScene:windowScene];
    self.window.backgroundColor = [UIColor whiteColor];
    
    CLTabbarController *tabbarVC = [[CLTabbarController alloc]init];
    CLBaseNavigationController *baseVC = [[CLBaseNavigationController alloc]initWithRootViewController:tabbarVC];
    self.window.rootViewController = baseVC;
    
    [self.window makeKeyAndVisible];

}

剩下就能按照之前项目的步骤进行开发了。