Xcode 11新建项目多了Scenedelegate？

根据官方介绍，Scenedelegate是给iPad分屏使用的，而且需要 iOS 13+ 才能用，如果不需要，那么可以按照以下步骤删除。

1. 删除Scenedelegate的".h"和".m"文件；

2. 删除Info.plist文件中的Application Scene Manifest配置；

3. 删除AppDelegate.m文件中的两个管理Scenedelegate生命周期代理方法：

- (UISceneConfiguration *)application:(UIApplication *)application configurationForConnectingSceneSession:(UISceneSession *)connectingSceneSession options:(UISceneConnectionOptions *)options {
// Called when a new scene session is being created.
// Use this method to select a configuration to create the new scene with.
return [[UISceneConfiguration alloc] initWithName:@"Default Configuration" sessionRole:connectingSceneSession.role];
}

And

- (void)application:(UIApplication *)application didDiscardSceneSessions:(NSSet *)sceneSessions {
// Called when the user discards a scene session.
// If any sessions were discarded while the application was not running, this will be called shortly after application:didFinishLaunchingWithOptions.
// Use this method to release any resources that were specific to the discarded scenes, as they will not return.
}

4. 在AppDelegate.h中，添加window属性：

@property (strong, nonatomic) UIWindow *window;