更改Apple Watch的初始接口控制器？

Question

有人知道如何在ExtensionDelegate中执行此操作吗？以下是我在AppDelegate for iPhone中的表现

self.window = [[UIWindow alloc] initWithFrame:UIScreen.mainScreen.bounds];
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStory" bundle:nil];
UIViewController *viewController = [storyboard instantiateViewControllerWithIdentifier:@"2ndScreen"];                                                                                                           
self.window.rootViewController = viewController;
[self.window makeKeyAndVisible];