不同的初始视图控制器

Question

我正在构建一个应用程序，用户可以在其中从另一个 ViewController 中选择一个项目，然后打开一个拆分 ViewController。我发现我无法将另一个 ViewController 设置为初始值，但我已经找到了第二个解决方案。

我将拆分视图设置为初始视图，并在 viewDidAppear 方法上导航到假初始 ViewController，就好像它是初始的一样。然后将选定的项目设置在全局变量中，并像这样关闭项目页面：

[self dismissModalViewControllerAnimated:YES]

打开splitview。

我的问题： 我可以使用这种方法吗？如果应用按预期运行，苹果会批准吗？

谢谢！

编辑：

这段代码在我的AppDelegate.m里，应该改成什么？

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
UISplitViewController *splitviewController = (UISplitViewController *)self.window.rootViewController;
UINavigationController *navigationController = [splitviewController.viewControllers lastObject];
splitviewController.delegate = (id)navigationController.topViewController;
return YES;
}

编辑 2：

// Override point for customization after application launch.
UISplitViewController *splitviewController = (UISplitViewController *)self.window.rootViewController;
UINavigationController *navigationController = [splitviewController.viewControllers lastObject];
splitviewController.delegate = (id)navigationController.topViewController;

如何将 self.window.rootViewController 引用到 SplitViewController？这样它就不会认为这个视图控制器会“托管”拆分视图？

编辑 3：

// Close the ProjectsViewController and open the selected project
[self presentViewController:_detailViewController animated:YES completion:^{
    [[[[UIApplication sharedApplication] delegate] window] setRootViewController:_detailViewController];
}];

编辑 4：

* 由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：“应用程序试图以模态方式呈现拆分视图控制器

方法与按钮链接：

-(void)selectedProject {
// The user opened a project

// Override point for customization after application launch.
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; // assuming your split view controller in storyboard with name "Main" in project's main bundle
UIViewController *splitViewController = [mainStoryboard instantiateViewControllerWithIdentifier:@"splitVC"];

UISplitViewController *splitviewController = (UISplitViewController *)splitViewController;
UINavigationController *navigationController = [splitviewController.viewControllers lastObject];
splitviewController.delegate = (id)navigationController.topViewController;

// Close the ProjectsViewController and open the selected project
[self presentViewController:splitViewController animated:YES completion:^{
    [[[[UIApplication sharedApplication] delegate] window] setRootViewController:splitViewController];
}];
}

显示项目页面：

- (IBAction)closeProject:(id)sender {
// Show the selectSubjectBanner
_selectSubjectBanner.hidden = NO;

// Save the current subject in case the user edited it
[self saveCurrentSubject];

// Present the ProjectsViewController
[self performSegueWithIdentifier:@"projectsSegue" sender:nil];
}
}

关闭项目页面：

- (void)selectedProject {
// The user opened a project

UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; // assuming your split view controller in storyboard with name "Main" in project's main bundle
UISplitViewController *splitViewController = (UISplitViewController *)[mainStoryboard instantiateViewControllerWithIdentifier:@"splitVC"];

UINavigationController *navigationController = [splitViewController.viewControllers lastObject];
splitViewController.delegate = (id)navigationController.topViewController;

// Close the ProjectsViewController and open the selected project
[UIView transitionFromView:[[[[[UIApplication sharedApplication] delegate] window] rootViewController] view]
                    toView:splitViewController.view
                  duration:0.5
                   options:UIViewAnimationOptionTransitionFlipFromLeft
                completion:^(BOOL finished) {
                    [[[[UIApplication sharedApplication] delegate] window] setRootViewController:splitViewController];
                }];
}

Answer 1

最好设置窗口的rootViewController

[[[[UIApplication sharedApplication] delegate] window] 
                     setRootViewController:yourViewController];

编辑：这是如何从情节提要中实例化视图控制器的代码，

UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; // assuming your split view controller in storyboard with name "Main" in project's main bundle
UIViewController *splitViewController = [mainStoryboard instantiateViewControllerWithIdentifier:@"splitVC"];

确保在 Storyboard、Identity Inspector 选项卡、splitVC（例如）中为视图控制器设置 Storyboard ID

编辑： 所以，UISplitViewController 本身就是一个容器视图控制器，因此我们不能在 UINavigationController、UITabBarController、add as childViewController、.. 等中保存它。而且我们也不能呈现它模态的，因此我们没有得到动画演示。 UISplitViewController 应该是窗口的rootViewController。在 rootViewController 和 splitViewController 之间获得动画转换的最简单方法是使用 UIView 的 transitionFromView 类方法并在视觉上交换它们的视图，同时更改 rootViewController 属性。这是您编辑的代码。

- (void)selectedProject {
    // The user opened a project

    UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; // assuming your split view controller in storyboard with name "Main" in project's main bundle
    UISplitViewController *splitViewController = (UISplitViewController *)[mainStoryboard instantiateViewControllerWithIdentifier:@"splitVC"];

    UINavigationController *navigationController = [splitviewController.viewControllers lastObject];
    splitViewController.delegate = (id)navigationController.topViewController;

    // Close the ProjectsViewController and open the selected project
    [UIView transitionFromView:[[[[[UIApplication sharedApplication] delegate] window] rootViewController] view]
                        toView:splitViewController.view
                      duration:0.5
                       options:UIViewAnimationOptionTransitionFlipFromLeft
                    completion:^(BOOL finished) {
                        [[[[UIApplication sharedApplication] delegate] window] setRootViewController:splitViewController];
                    }];
}

Answer 2

您可以将任何视图控制器设置为初始视图控制器

您不能在 viewDidAppear 方法中启动视图控制器。太糟糕了。

在考虑应用转换时，Apple 不会拒绝应用。这取决于开发人员。

您可以通过重置窗口的rootviewcontroller来设置任何viewcontroller

而不是故事板检查您的逻辑并从 appdelegate 启动必要的视图控制器。分别替换Seryozha提到的窗口rootViewController