Question

I have seen this example on Apple’s website before, but for some reason, I cannot find it and am brainfarting. I created a TestViewController.h and .m file that subclass from UIViewController and have a .xib. In the TestAppDelegate.h, I have:

@interface TestAppDelegate : NSObject <UIApplicationDelegate> {

    TestViewController *rootController;
}

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

in TestAppDelegate.m, I have:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    [self.window addSubview:rootController.view];
    [self.window makeKeyAndVisible];
    return YES;
}

Then in my MainWindow.xib, I drag a ViewController, change the class to TestViewController, control drag the outlet from TestAppDelegate to TestViewController. It builds fine, but when I run it I get:

*** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<TestViewController 0x4d06570> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key label.'

I cannot remember what I’m missing in these steps. Any help would be appreciated. Thanks.

Answer 1

@interface TestAppDelegate : NSObject <UIApplicationDelegate> {

TestViewController *rootController;
}

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

in TestAppDelegate.m, I have:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:    (NSDictionary *)launchOptions
{
// Override point for customization after application launch.
[self.window addSubview:rootController.view];
[self.window makeKeyAndVisible];
return YES;
}

IF IT IS THE CODE YOU ARE REALLY USING THEN ADD FOLLOWING LINE TO YOUR INTERFACE:

UIWindow *window;

AND CHECK IF IT HELPS.