启动导航控制器

Question

我在app delegate didFinishLaunchWithOptions

中实现了以下代码

NotificationsViewController *viewController = [[NotificationsViewController alloc] init];
UINavigationController *nav = [[UINavigationController alloc]
                        initWithRootViewController:viewController];

_window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
_window.rootViewController = nav;
[_window makeKeyAndVisible];

当它到达最后一行代码时，编译器告诉我：

Application windows are expected to have a root view controller at the end of application launch

我做错了什么？我没有将window.rootviewController设置为nag？

Answer 1

您不需要创建uiwondow。 删除所有分配和inits _window的代码 现在 试试这个：self.window.rootViewController = nav;