是否有可能使presentModalViewController成为UINavigation控制器？

Question

我正试图使presentModalViewController在应用程序启动时出现。我可以使presentModalViewController出现好，但是当我尝试使它成为UINavigation控制器时，我看到的只是一个空白的UINavigationController。

我班概述如下定义：

#import <UIKit/UIKit.h> 
@class Login; 

@interface Overview : UINavigationController { 

} 

-(IBAction) btnRegistrationPressed; 
-(IBAction) btnLoginPressed; 


@end 

然后在委托我这样做：

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

    // Override point for customization after application launch. 

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

    Overview *overviewViewController = [[Overview alloc] initWithNibName:@"Overview" bundle:nil]; 

    [self.tabBarController presentModalViewController:overviewViewController animated:YES]; 
    [overviewViewController release]; 
    [self.window makeKeyAndVisible]; 

    return YES; 
} 

我也有一个Overview.xib中，我在UiNavigation控制器从拖图书馆。下面的视图控制器被设置为一个名为test的类，它将在屏幕上显示一条消息。

当我启动时，我看到的只是一个空白的UINavigationController。

任何想法？

Answer 1

你试过像下面

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

// Override point for customization after application launch. 

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


Overview *overviewViewController = [[Overview alloc] initWithNibName:@"Overview" bundle:nil]; 

UINavigationController *nav_obj = [[UINavigationController alloc] initWithRootViewController:overviewViewController ]; 

[self.tabBarController presentModalViewController:nav_obj animated:YES]; 
[overviewViewController release]; 
[self.window makeKeyAndVisible]; 

return YES; 

}