iphone - 在 iPhone 应用程序中使用 tabBar 时出现黑屏

Question

我正在我的 iPhone 应用程序中添加 UITabBarController。我在 TabsAppDelegate.h 中提到过它，如下所示

#import <UIKit/UIKit.h>

@interface TabsAppDelegate : NSObject <UIApplicationDelegate,   UITabBarControllerDelegate> {
    UIWindow *window;
    UITabBarController *tabBarController;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;


@end

和我的 TabsAppDelegate.m didFinishLaunchingWithOptions 方法

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



    // Add the tab bar controller's view to the window and display.
    [window addSubview:tabBarController.view];
    [window makeKeyAndVisible];

    return YES;
}

现在，在 MainWindow.xib 中，我添加了选项卡栏 Controller 并与 tabBarController 建立连接。后来我创建了 FirstViewController 和 SeconViewController 这是两个 ViewController。现在，在第一个选项卡上，我添加了 FirstViewController.xib，在第二个选项卡上，我使用构建器界面添加了 SecondViewController.xib 文件。

但是当我运行该项目时它显示黑屏。需要你的帮助。提前致谢。

Answer 1

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


        UIViewController *viewController1 = [[[RootViewController alloc] initWithNibName:@"RootViewController" bundle:nil] autorelease];
                UINavigationController *navviewController1=[[UINavigationController alloc]initWithRootViewController:viewController1];
                navviewController1.title = @"FirstTitle";
        //        navviewController1.navigationBarHidden=YES;

        UIViewController *viewController2 = [[[yourviewController2 alloc] initWithNibName:@"yourviewController2" bundle:nil] autorelease];
                UINavigationController *navviewController2=[[UINavigationController alloc]initWithRootViewController:viewController2];
        //        navviewController2.navigationBarHidden=YES;
                navviewController2.title = @"SecondTitle";

        UIViewController *viewController3 = [[[yourviewController3 alloc] initWithNibName:@"yourviewController2" bundle:nil] autorelease];
                UINavigationController *navviewController3=[[UINavigationController alloc]initWithRootViewController:viewController3];
        //        navviewController3.navigationBarHidden=YES;
                navviewController3.title = @"ThirdTitle";

               //..... and so on depend on your requirement 

        self.tabBarController = [[[UITabBarController alloc] init] autorelease];
        self.tabBarController.viewControllers = [NSArray arrayWithObjects:navviewController1, navviewController2 , navviewController3 ,nil];
        self.window.rootViewController = self.tabBarController;
        [self.window makeKeyAndVisible];
    }

试试这个，你只是忘记添加 rootViewController