Question

I need to initialize an object of an object in my AppDelegate at startup. Whenever I try to access the ivar somewhere else all that is returned is null.

What I’m doing can be simplified as

//AppDelegate.h:
@interface AppDelegate : UIResponder <UIApplicationDelegate> {
    NSString* someString;
}

@property (nonatomic, copy)   NSString* someString;

and then in the AppDelegate.m

//AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    someString = @"Hello World!";
    NSLog(@"%@",someString);
}

This is what I do when I access the NSString-object

//ViewController.m
- (void)viewDidLoad {
    [super viewDidLoad];
    AppDelegate *delegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];

    NSLog(@"%@",delegate.someString);
}

The output text is

• 2012-09-30 22:26:45.125 Labor3[22524:f803] Hello World!
• 2012-09-30 22:26:45.127 Labor3[22524:f803] (null)

without any warnings or errors.

The problem I’m having is a bit more complicated but the essentials stay the same and I can’t even get the above example to work. Any hint is appreciated.

Answer 1

Add

@synthesize someString;

After

@implementation AppDelegate

in your app-delegate .m file.