设备上的黑屏； 模拟器工作正常

Question

I am writing an iOS app with a navigation controller. When I open it up on the Simulator, it runs fine. When I run it on the device, a blank screen is displayed below the status bar. Plus I can't figure out where my RootViewController is made to be the default view (which I suspect is the root of my problem).

@class RootViewController;

@interface MyAppDelegate : NSObject <UIApplicationDelegate> {
    UIWindow *window;
    RootViewController *viewController;

    UINavigationController *navigationController;
}

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

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

    // Override point for customization after application launch.

    // Set the navigation controller as the window's root view controller and display.
    self.window.rootViewController = self.navigationController;
    [self.window makeKeyAndVisible];

    // ...

    return YES;
}

RootViewController.m

- (void)viewDidLoad {
    [super viewDidLoad];
    self.title = @"Main Menu";
}

No viewWillAppear, viewDidAppear, etc.

Displays a table of 0 elements.

- (UITableViewCell *)tableView:(UITableView *)tv
        cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    tv.backgroundColor = [UIColor whiteColor];

    UITableViewCell *cell;
    if (indexPath.row == 0)
        cell = newsCell;
    else if (indexPath.row == 1)
        cell = configureCell;
    else if (indexPath.row == 2)
        cell = aboutCell;

    return cell;
}

- (NSInteger)tableView:(UITableView *)tv numberOfRowsInSection:(NSInteger)section
{
    return 0;
}

#pragma mark UITableViewDelegate Methods


- (CGFloat)tableView:(UITableView *)tv
heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return 84;
}

- (void) tableView:(UITableView *)tv
didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (0 == indexPath.row)
    {
    }
    else if (1 == indexPath.row)
    {
    }
    else if (2 == indexPath.row)
    {
    }
}


#pragma mark -
#pragma mark Memory management

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Relinquish ownership any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    // Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
    // For example: self.myOutlet = nil;
}


- (void)dealloc {
    [super dealloc];
    [tableView release];
    [newsCell release];
    [configureCell release];
    [aboutCell release];
}

RootViewController.h

@interface RootViewController : UIViewController
<UITableViewDataSource, UITableViewDelegate>
{
    UITableView *tableView;
    IBOutlet UIView *displaySplashScreen;
    IBOutlet UITableViewCell *newsCell, *configureCell, *aboutCell;
}

@property (nonatomic, retain) IBOutlet UITableView *tableView;

Answer 1

There are a few issues here. First, your AppDelegate header should read:

@class RootViewController;

@interface MyAppDelegate : NSObject <UIApplicationDelegate> {
    UIWindow *window;
    RootViewController *rootViewController;
}
@property (nonatomic, retain) IBOutlet UIWindow *window;

@end

Then, in the implementation, add the root to the navigation controller and the navController to the window like this:

#import "RootViewController.h"

@implementation MyAppDelegate

@synthesize window;

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

    rootViewController = [[RootViewController alloc] init];
    UINavigationController *navController = [[UINavigationController alloc] 
                                             initWithRootViewController:rootViewController];

    [window addSubview:[navController view]];
    [self.window makeKeyAndVisible];

    return YES;
}

Answer 2

PengOne's answer is correct, except I'd make one small change. Do this:

#import "RootViewController.h"

@implementation MyAppDelegate

@synthesize window;

- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    rootViewcontroller = [[RootViewController alloc] init];
    UINavigationController *navController = [[UINavigationController alloc] 
                                         initWithRootViewController:rootViewController];

    self.window.rootViewController = navController;

    [self.window makeKeyAndVisible];
    return YES;
}

It's a better way to show a nav controller. As PengOne also said, it has to be a problem with your Interface Builder file. Unhook everything then hook it up again to see if the problem persists. If it does, check to make sure everything is named correctly. Good luck!