需要帮助来了解UIViewController和UIWindow初始化 [英] Need help understanding UIViewController and UIWindow initialization

问题描述

我想知道是否有人可以解释下面的代码块，因为我不太了解.

I was wondering if anyone could explain the following block of code because I don't really understand it.

self.viewController = [[RootViewController alloc] initWithNibName:@"RootViewController" bundle:nil];
self.navigationController = [[ UINavigationController alloc ] initWithRootViewController:self.viewController ];
self.window.rootViewController = self.navigationController;
[self.window makeKeyAndVisible];

然后，当您要展示新的vc时，您可以执行以下操作:

Then when you want to present a new vc you can do this:

OtherViewController *ovc = [[ OtherViewController alloc ] initWithNibName:@"OtherViewController" bundle:nil ];
[ self.navigationController pushViewController:ovc animated:YES ];

要返回，请执行以下操作:

To go back do this:

[ self.navigationController popViewControllerAnimated:YES ];

推荐答案

导航控制器需要一个根"视图控制器，这是它管理的视图控制器堆栈中的底部视图控制器.

A navigation controller needs a "root" view controller, which is the bottom view controller in the stack of view controllers it manages.

#1 self.viewController = [[RootViewController alloc] initWithNibName:@"RootViewController" bundle:nil];
#2 self.navigationController = [[ UINavigationController alloc ] initWithRootViewController:self.viewController ];
#3 self.window.rootViewController = self.navigationController;
[self.window makeKeyAndVisible];
#4 [self.window makeKeyAndVisible];

第1行创建一个类"RootViewController"(必须是自定义视图控制器类)的视图控制器.它从同名的nibfile加载视图控制器的视图.这类似于使用InstantiateViewControllerWithIdentifier从情节提要中加载视图控制器，不同之处在于，您必须指定要创建的视图控制器的类以及正在加载

Line 1 creates a view controller of class "RootViewController" (which must be a custom view controller class.) It loads the view controller's views from a nibfile of the same name. This is similar to using instantiateViewControllerWithIdentifier to load a view controller from a storyboard, except that you have to specify the class of view controller you're creating, and the nibfile you're loading the

第2行使用新创建的"RootViewController"作为根视图控制器来创建导航控制器

Line 2 creates a navigation controller with the newly created "RootViewController" as it's root view controller

第3行将导航控制器安装为应用程序窗口的根视图控制器.

Line 3 installs the navigation controller as the root view controller of the application window.

第4行使应用程序窗口成为活动窗口.

Line 4 makes the app window the active window.

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