UINavigationController在运行编译时不显示

Question

编辑：工作，请参阅下面的代码。

在一个应用程序上工作，现在我有AppDelegate类和一个自定义UINavigationController类。我现在的代码非常简单，我觉得我已经正确设置了XIB。构建成功，没有错误。但是当应用程序启动时，导航控制器不会显示。我没有看到导航栏和表格视图。我看到的只是一个空白的屏幕。这里是我的大部分代码：

// 
// FTPPhotosAppDelegate.h 
// FTPPhotos 
// 
// Created by Aaron McLeod on 11-05-30. 
// Copyright 2011 __MyCompanyName__. All rights reserved. 
// 

#import <UIKit/UIKit.h> 
#import "RootViewController.h" 

@interface FTPPhotosAppDelegate : NSObject <UIApplicationDelegate> { 
    UINavigationController *navigationController; 
    RootViewController *rootViewController; 
} 

@property (nonatomic, retain) UINavigationController *navigationController; 
@property (nonatomic, retain) IBOutlet UIWindow *window; 

@property (nonatomic, retain) RootViewController *rootViewController; 

@end 


// 
// FTPPhotosAppDelegate.m 
// FTPPhotos 
// 
// Created by Aaron McLeod on 11-05-30. 
// Copyright 2011 __MyCompanyName__. All rights reserved. 
// 

#import "FTPPhotosAppDelegate.h" 

@implementation FTPPhotosAppDelegate 


@synthesize window=_window; 

    @synthesize navigationController, rootViewController; 

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 
    navigationController = [[UINavigationController alloc] init]; 

    rootViewController = [[RootViewController alloc] init]; 
    [self.navigationController pushViewController:rootViewController animated:NO]; 
    [self.window addSubview:[self.navigationController view]];  
    [self.window makeKeyAndVisible]; 
    return YES; 
} 


@interface RootViewController : UITableViewController<UIImagePickerControllerDelegate> { 
    NSMutableArray *photos; 
    UIImagePickerController *picker; 
    UIBarButtonItem *addPhotoButton; 
} 

@property (nonatomic, retain) NSMutableArray *photos; 
@property (nonatomic, retain) UIImagePickerController *picker; 
@property (nonatomic, retain) IBOutlet UIBarButtonItem *addPhotoButton; 

- (void) loadPhotos; 
- (IBAction) addPhoto; 
- (UIImage*)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize; 
@end 


#import "RootViewController.h" 

@implementation RootViewController 
@synthesize photos, picker, addPhotoButton; 

- (void)viewDidLoad 
{ 
    self.photos = [[NSMutableArray alloc] initWithCapacity:50]; 
    [self loadPhotos]; 
    [super viewDidLoad]; 
} 

任何想法？以下是XIB，

的屏幕截图。

让我知道你是否需要更多信息。

Answer 1

取而代之的是一个根视图控制器，使它成为UINavigationController *navigationController。

然后在applicationDidFinishLaunching，说

navigationController = [[UINavigationController alloc]init]; 
FirstViewController *firstView = [FirstViewController alloc]init]; 
[self pushViewController:firstView animated:NO]; 
firstView.title = @"TITLE"; 
[self addSubview:navigationController.view]; 

编辑：一些示例代码我在我的一个应用

AppDelegate.h

#import <UIKit/UIKit.h> 

@interface DragonAge2AppDelegate : NSObject <UIApplicationDelegate> { 
UIWindow *window; 
UINavigationController *navigationController; 
} 

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

@end 

AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {  
TitleClass *titlePage = [[TitleClass alloc]init]; 

navigationController = [[UINavigationController alloc]init]; 
titlePage.title = @"Dragon Age 2"; 
[navigationController pushViewController:titlePage animated:NO]; 
[titlePage release]; 

// Override point for customization after application launch. 
[window addSubview:navigationController.view]; 
[self.window makeKeyAndVisible]; 

return YES; 
} 

Answer 2

您需要检查一些要点：

• 在执行application:didFinishLaunchingWithOptions:的代码，当你运行应用程序？在此代码中添加一个NSLog(@"app launched")或在其中设置一个断点来检查它。如果未被调用，则您的FTPPhotosAppDelegate对象可能未被设置为XIB中的UIApplication单身人员的代表（如果您使用标准模板创建应用程序，此连接应默认完成），但值得检查
• 您的AppDelegate的navigationControllerIBOutlet已正确连接到XIB中的实际UINavigationController？检查（使用NSLog或断点）它不是nil。
• 与XIB中的UINavigationController对象的视图IBOutlet相同：请检查它是否正确连接，而不是nil。