相关疑难解决方法(0)

我在控制台中收到以下错误:

应用程序在应用程序启动结束时应具有根视图控制器

以下是我的application:didFinishLaunchWithOptions方法:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    // Set Background Color/Pattern
    self.window.backgroundColor = [UIColor blackColor];
    self.tabBarController.tabBar.backgroundColor = [UIColor clearColor];
    //self.window.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"testbg.png"]];

    // Set StatusBar Color
    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackTranslucent];

    // Add the tab bar controller's current view as a subview of the window
    self.window.rootViewController = self.tabBarController;
    [self.window makeKeyAndVisible];
    return YES;
}

在Interface Builder中,UITabBarController代理连接到App Delegate.

有谁知道如何解决这个问题？

我正在尝试将我的iPhone应用程序转换为通用应用程序.我将设备切换到Universal并让Xcode为我做了一个MainWindow-iPad.xib的事情,现在当我在iPhone模拟器中运行应用程序时,它工作正常,但是当我在iPad模拟器中运行它时,我得到一个白色屏幕和Application windows are expected to have a root view controller at the end of application launch错误.我已经阅读了一些关于同样问题的其他帖子,但没有一个仅限于一个设备.

这是我的application:didFinishLaunchWithOptions:方法:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

 /* some dropbox setup stuff */


// INIT VIEW AND CORE DATA
RootViewController *rootViewController = [[RootViewController alloc] initWithNibName:@"RootViewController" bundle:nil];

NSManagedObjectContext *context = [self managedObjectContext];
if (!context) {
    // Handle the error.
}

rootViewController.managedObjectContext = context;

UINavigationController *aNavigationController = [[UINavigationController alloc] initWithRootViewController:rootViewController];
self.navigationController = aNavigationController;

[_window addSubview:[_navigationController view]];
[_window makeKeyAndVisible];

[rootViewController release];
[aNavigationController release]; …