动态更改导航控制器的 rootviewcontroller

Question

我正在尝试将RootViewController 更改为NavigationController 中的didFinishLaunchingWithOptions。
但我不知道该怎么做。

我也浏览过这个链接：
http://starterstep.wordpress.com/2009/03/05/changing-a-uinavigationcontroller%E2%80%99s-root-view-controller/

这是我在didFinishLaunchingWithOptions中的代码：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    UIViewController *rootController=[[HomePageController alloc] initWithNibName:@"HomePageController" bundle:nil];
    navigationController=[[UINavigationController alloc] initWithRootViewController:rootController];

//    presentation=[[PresentationController alloc]initWithNibName:@"PresentationController" bundle:nil];
//    
//    navigationController=[[UINavigationController alloc]initWithRootViewController:presentation];
//    
//    presentationList=[[PresentationListController alloc]initWithNibName:@"PresentationListController" bundle:nil];
//    
//    UINavigationController *listnavigation = [[UINavigationController alloc] initWithRootViewController:presentationList];
//    
//    revealer=[[ZUUIRevealController alloc]initWithFrontViewController:navigationController rearViewController:listnavigation];

    [self.window addSubview:navigationController.view];

    [self.window makeKeyAndVisible];
    return YES;
}

现在我评论然后运行应用程序来更改rootviewcontroller。然而，这不是实际的方法。

我们将不胜感激。

Answer 1

而不是这个：

[self.window addSubview:navigationController.view];

把这个：

self.window.rootViewController = navigationController;

Answer 2

导航控制器不关心它的根视图控制器是什么类型的视图控制器，只要它是 UIViewController 的子类即可。所以你可以像这样使用指向 UIViewController 的指针：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    UIViewController *rootController = nil;
    if (iWantHomePageController)
    {
        rootController = [[HomePageController alloc] initWithNibName:@"HomePageController" bundle:nil];
    }
    else if (iWantPresentationController)
    {
        rootController = [[PresentationController alloc] initWithNibName:@"PresentationController" bundle:nil];
    }
    else if (iWantPresentationListController)
    {
        rootController = [[PresentationListController alloc] initWithNibName:@"PresentationListController" bundle:nil];
    }

    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:rootController];

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.rootViewController = navController;

    [self.window makeKeyAndVisible];
    return YES;
}

Answer 3

这对我来说真的很好用：

self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

/*
    both *navigationController and *viewController are declared 
    as properties in the .h file 
*/
[self setViewController:[[[RootViewController alloc] initWithNibName:@"RootViewController" bundle:nil] autorelease]];
[self setNavigationController:[[[UINavigationController alloc] initWithRootViewController:self.viewController]autorelease]];
[self.window setRootViewController:[self navigationController]];
[self.window makeKeyAndVisible];